Irresistible Mushroom and Caramelized Onion Phyllo Tart Recipe

Why You’ll Love This Mushroom and Caramelized Onion Phyllo Tart

This is the kind of tart that fits so many moments:

• Elegant enough for guests, but simple enough for a weeknight
• Crunchy, flaky phyllo without needing a mixer or rolling pin
• Flexible: add cheese, herbs, a drizzle, or keep it minimalist
• Perfect as:
  • a party appetizer
  • a brunch centerpiece
  • a light dinner with a big salad

Ingredients for Mushroom and Caramelized Onion Phyllo Tart

For the phyllo tart base

• 10–14 sheets frozen phyllo (filo) dough, thawed
• 6–8 tbsp melted butter or olive oil (for brushing)
• Parchment paper (highly recommended)

Optional for the base (helpful!)

• 1–2 tbsp fine breadcrumbs (acts like a little “crisp insurance”)
• 1 tbsp grated parmesan (adds savory edge without heaviness)

For the caramelized onions

• 2 large onions (yellow or sweet), thinly sliced
• 2 tbsp olive oil (or a mix of oil + butter)
• 1/2 tsp salt (start small; adjust later)
• 1–2 tsp balsamic vinegar or a splash of wine (optional, but delicious)

For the mushrooms

• 450–500 g mushrooms (cremini + shiitake is fantastic)
• 1–2 tbsp olive oil
• 2 cloves garlic, minced
• 1–2 tsp fresh thyme leaves or 1/2 tsp dried thyme
• Black pepper

Optional finishing touches (choose your vibe)

• Crumbled goat cheese or feta
• Shredded Gruyère (melty + nutty)
• Chopped chives or parsley
• Toasted walnuts or pine nuts
• A drizzle of balsamic glaze (after baking)

Tools You’ll Need

• Large skillet (preferably heavy-bottomed)
• Sheet pan
• Parchment paper
• Pastry brush (or a spoon in a pinch)
• Cutting board + sharp knife

Step 1: Make the Caramelized Onions (Jammy + Golden)

Caramelizing onions is less about “tricks” and more about patience + heat control. Onions brown because their natural sugars break down and deepen in flavor as they cook.

How to do it

1. Heat a large skillet over medium heat.
2. Add oil (and butter if using).
3. Add sliced onions + a small pinch of salt.
4. Cook, stirring often at first, then periodically:
   • If onions start sticking, lower heat slightly
   • If the pan looks dry, add a tablespoon of water and scrape the browned bits

What you’re looking for

• Color: deep golden (not pale, not burnt)
• Texture: soft, silky, reduced
• Smell: sweet-savory and rich

Optional flavor boost

When onions are golden and reduced:

• Add 1–2 tsp balsamic or a splash of wine
• Stir 30–60 seconds to cook off sharpness

Set aside and let cool slightly.

Step 2: Cook the Mushrooms So They Brown (Not Steam)

Here’s the truth: mushrooms are already full of internal moisture, so the key is how you cook them—not whether they got a quick rinse. A brief wash won’t ruin them if your pan technique is solid.

Prep the mushrooms

• Wipe clean with a damp towel or
• Quick rinse + pat dry (especially if they’re gritty)

Sauté like a pro

1. Heat a skillet over medium-high.
2. Add oil.
3. Add mushrooms in a single layer (work in batches if needed).
4. Don’t stir constantly—give them time to release moisture, then brown.
5. Once they start browning:
   • Add garlic + thyme
   • Add black pepper
   • Add salt near the end (helps avoid watery mushrooms early)

Cook until:

• Most of the moisture is gone
• Edges are browned
• Pan looks “dry-ish,” not soupy

Set aside and let cool slightly.

Step 3: Build the Phyllo Tart Base (Crispy Layers)

Set up

• Heat oven to 190°C (375°F)
• Line a sheet pan with parchment

Layer the phyllo

1. Place 1 sheet of phyllo on the parchment.
2. Brush lightly with melted butter (or oil).
3. Add another sheet, slightly rotated or offset.
4. Repeat until you have 10–14 layers.

Tip for strength:
Rotate sheets every few layers so the grain runs in different directions—this helps the tart hold together.

Create a border

• Fold the outer 2–3 cm (1 inch) inward around the edges
• Brush the border well (it’s the prettiest part!)

Optional crisp insurance:

• Sprinkle a light dusting of breadcrumbs or parmesan over the center before adding fillings.

Step 4: Assemble the Filling (Best Order)

To keep everything crisp:

1. Spread caramelized onions evenly over the center (inside the border)
2. Add mushrooms over the top
3. Add optional cheese:
   • crumbled goat cheese/feta OR
   • shredded Gruyère
4. Finish with:
   • thyme leaves
   • black pepper
   • tiny pinch of flaky salt (optional)

Step 5: Bake Until Deeply Golden

Bake at 190°C (375°F) for 20–30 minutes.

How to know it’s done

• Phyllo edges are deep golden
• Bottom feels crisp when lifted slightly with a spatula
• Center looks set (not wet)

If edges brown too fast:

• Tent the border lightly with foil for the final 8–10 minutes.

Let cool 5–10 minutes before slicing—phyllo gets crispier as it rests.

Serving Ideas (Make It a Moment)

This tart is ridiculously versatile.

Serve it as:

• Appetizer: cut into small squares
• Brunch: pair with eggs and a bright salad
• Dinner: serve with a lemony arugula salad or a simple soup

Finishing touches that feel fancy

• A few fresh thyme sprigs
• Chopped chives
• Toasted walnuts
• A small drizzle of balsamic glaze (after baking)

Variations (Keep the Same Method, Change the Vibe)

1) Cheese variations

• Goat cheese + thyme (classic)
• Gruyère + black pepper (melty and bold)
• Feta + herbs (salty, punchy)
• Parmesan only (minimalist, crisp-friendly)

2) Herb swaps

• Thyme + rosemary (deep and woodsy)
• Chives + parsley (fresh and green)
• A pinch of chili flakes (gentle heat)

3) Add a “barrier layer” (extra crisp)

If you want maximum crunch:

• Thin spread of ricotta-like cheese
• Light sprinkle of breadcrumbs
• A few shavings of parmesan

4) Mini tartlets/party version

• Use muffin tin + phyllo squares
• Bake shorter time (watch closely)
• Perfect for finger-food trays

5) Extra toppings

• Caramelized shallots instead of onions
• Roasted garlic
• Toasted pine nuts
• A handful of baby spinach (wilt first so it’s not watery)

Make-Ahead Tips

You can prep almost everything in advance.

Best make-ahead plan

• Make onions up to 3 days ahead
• Cook mushrooms up to 2 days ahead
• Store both in the fridge, then bring closer to room temp before assembling

Can you assemble ahead?

Yes—briefly.

• Build the phyllo base
• Add cooled fillings
• Refrigerate 30–60 minutes max if needed
• Bake right before serving for best crispness

Storage + Reheating (Keep It Crispy)

Storage

• Cool completely
• Store in an airtight container in the fridge

Reheat (best method)

• Oven or toaster oven at 175°C (350°F) for 8–12 minutes
• This brings back the crisp phyllo crunch

Troubleshooting (Quick Fixes)

“My tart is soggy.”

Most common causes:

• Mushrooms weren’t cooked long enough
• Fillings were added while hot
• No “barrier layer” (breadcrumbs/parmesan)

Fix next time:

• Brown mushrooms more aggressively
• Cool fillings before assembling
• Add a light breadcrumb layer under onions

“My phyllo cracked everywhere.”

Likely:

• It dried out while you worked
• It wasn’t thawed gently

Fix next time:

• Thaw overnight in the fridge
• Keep the stack covered with a slightly damp towel
• Patch tears and keep going

“Edges browned too fast.”

• Tent edges with foil
• Move the rack slightly lower in the oven

“It tastes flat.”

• Add a pinch more salt to the mushrooms at the end
• Finish with fresh herbs
• Add a sharper cheese (feta/goat) or a tiny balsamic drizzle after baking

FAQs: Mushroom and Caramelized Onion Phyllo Tart

How do you keep phyllo dough from drying out?

• Keep unused sheets covered with a clean, slightly damp towel
• Pull one sheet at a time
• Work steadily and keep butter/oil ready

Can I make this tart ahead of time?

Yes—best approach:

• Make onions + mushrooms ahead
• Assemble and bake closer to serving for peak crispness

How do I keep a phyllo tart crispy after baking?

• Cool 5–10 minutes before slicing
• Store airtight
• Reheat in the oven (not microwave)

What mushrooms work best here?

• Cremini (great base)
• Shiitake (extra depth)
• Oyster (delicate texture)
  A mix is ideal for a more complex mushroom flavor.

Conclusion

This Mushroom and Caramelized Onion Phyllo Tart is proof that simple ingredients, handled with care, can create something truly memorable. From the crisp, golden phyllo layers to the rich sweetness of caramelized onions and the deep, savory character of mushrooms, every bite delivers contrast, balance, and elegance.

Irresistible Mushroom and Caramelized Onion Phyllo Tart Recipe

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• Author: Velma
• Total Time: PT1H20M
• Yield: 8 slices 1x
• Diet: Vegetarian

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Description

This Mushroom and Caramelized Onion Phyllo Tart is savory, flaky, and deeply flavorful. Crispy layers of buttery phyllo dough cradle a rich filling of golden caramelized onions, earthy mushrooms, herbs, and cheese. Elegant yet comforting, it’s perfect for brunch, holidays, dinner parties, or a meatless main paired with a fresh salad.

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Ingredients

Scale 1x2x3x

For the Phyllo Base

• 8–10 sheets phyllo dough, thawed
• ½ cup unsalted butter, melted (or olive oil)

For the Filling

• 2 tbsp olive oil
• 2 large onions, thinly sliced
• 12 oz mushrooms (cremini, button, or mixed), sliced
• 2 cloves garlic, minced
• 1 tsp fresh thyme leaves (or ½ tsp dried)
• ½ tsp salt
• ½ tsp black pepper

For the Custard

• 2 large eggs
• ½ cup heavy cream (or half-and-half)
• ½ cup grated Gruyère, Swiss, or Parmesan cheese

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Instructions

1. Caramelize the Onions

1. Heat olive oil in a skillet over medium-low heat.
2. Add onions and cook 20–25 minutes, stirring often, until soft and deeply golden.
3. Season lightly with salt and set aside.

2. Cook the Mushrooms

1. In the same skillet, add mushrooms and cook 6–8 minutes until the moisture evaporates.
2. Add garlic, thyme, salt, and pepper; cook 30 seconds until fragrant.
3. Combine the mushrooms with caramelized onions and let them cool slightly.

3. Prepare the Phyllo Crust

1. Preheat oven to 375°F (190°C).
2. Brush a tart pan (9–10 inch) with butter.
3. Lay one sheet of phyllo in the pan, brushing lightly with butter.
4. Repeat with remaining sheets, rotating slightly and letting edges overhang.

4. Assemble

1. Spread the onion-mushroom mixture evenly over the phyllo base.
2. Whisk eggs and cream, then stir in grated cheese.
3. Pour custard evenly over the filling.
4. Fold or trim excess phyllo edges.

5. Bake

• Bake 30–35 minutes, until filling is set and phyllo is golden and crisp.

6. Serve

• Rest 10 minutes before slicing.
• Serve warm or at room temperature.

Notes

• Keep phyllo covered with a damp towel while working.
• Add spinach or leeks for variation.
• Gruyère adds richness; feta gives a sharper contrast.

• Prep Time: PT20M
• Cook Time: PT60M
• Category: Appetizer
• Method: Baked
• Cuisine: European

Nutrition

• Serving Size: 1 slice
• Calories: 320 kcal
• Sugar: 6g
• Sodium: 380mg
• Fat: 22g
• Saturated Fat: 12g
• Unsaturated Fat: 10g
• Trans Fat: 0g
• Carbohydrates: 22g
• Fiber: 3g
• Protein: 9g
• Cholesterol: 85mg