Savory Mushroom Tart with Caramelized Onions and Thyme

Savory sautéed mushrooms, three Italian cheeses and flaky puff pastry combine in this easy mushroom tart—an ideal appetizer or light meal.

There’s something comforting about the scent of baking in winter, and this mushroom tart is a savory recipe that fills the house while doubling as an easy lunch or appetizer. Using store-bought puff pastry keeps the tart quick and effortless without sacrificing flavor or presentation.

We enjoy savory tarts year-round. My zucchini tomato tart and heirloom tomato tart are summer favorites, and this mushroom tart brings that same flaky, cheesy appeal into the cooler months. It works beautifully as a shareable appetizer or sliced and served with a green salad for a light dinner.

Why You’ll Love This Mushroom Tart

Simple but impressive. The tart is easy to assemble yet looks and tastes like something special.

Rich, balanced flavors. Earthy sautéed mushrooms paired with a creamy ricotta base, melting mozzarella and a shower of Parmesan make every bite satisfying.

Versatile for any occasion. Serve it warmed or at room temperature as an elegant appetizer for guests or a cozy weeknight meal.

Customizable. Swap cheeses, herbs or mushroom varieties to suit your taste. You can use a homemade crust if you prefer, or cut the puff pastry into smaller squares for individual tarts.

You can make a vegetarian version by choosing a Parmesan-style cheese made without animal rennet or using fully vegetarian/vegan cheese and a vegan puff pastry.

Ingredient Notes

Puff pastry

Store-bought puff pastry is convenient—keep it cold while working with it and follow package thawing instructions. If you find an all-butter puff pastry, it will improve the flavor.

Olive oil

Olive oil gives the mushrooms a pleasant flavor; substitute butter for a richer finish if you prefer.

Shallot

Shallots add a subtle sweetness to the filling. If unavailable, a small red onion works well.

Mushrooms

Mixed wild mushrooms give more depth, but cremini, shiitake, portobello or regular button mushrooms all work fine.

Garlic

Garlic adds savory depth—use less or omit if you’re sensitive to it, but fresh garlic gives the best flavor.

Fresh thyme

Fresh herbs brighten the tart. If you don’t have thyme, try rosemary or oregano; fresh basil makes a nice garnish.

Ricotta cheese

Ricotta creates a creamy base. Alternatives like cottage cheese, goat cheese, mascarpone or crème fraîche will change the flavor and texture slightly but work well.

Parmesan cheese

Freshly grated Parmesan is best for flavor, though pre-grated is acceptable.

Mozzarella

Mild mozzarella melts nicely. Gruyère or a mild cheddar can be substituted for a different flavor profile.

Egg

The egg wash (egg mixed with water) gives the pastry its glossy, golden edge.

Step-by-Step Instructions

1. Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
2. Heat 1 tablespoon olive oil in a large skillet over medium heat. Add thinly sliced shallot and cook about 3 minutes until lightly browned, lowering the heat if needed.
3. Add the sliced mushrooms, 1/4 teaspoon salt and a pinch of black pepper. Cook until the mushrooms release their liquid and then brown, about 15 minutes.
4. Stir in minced garlic and fresh thyme and cook for about 1 minute more. Remove from heat and let the mixture cool slightly.
5. In a bowl, combine 1/2 cup ricotta, 1/4 cup grated Parmesan, the remaining tablespoon of olive oil, 1/4 teaspoon salt and pepper to taste. Mix until smooth.
6. On a lightly floured surface, roll the thawed puff pastry slightly to smooth creases (roughly 11×12 inches depending on the sheet). Transfer to the prepared parchment-lined baking sheet.
7. Lightly score a 1/2-inch border around the pastry with a knife (don’t cut through). Dock the inner rectangle evenly with a fork.
8. Spread the ricotta mixture over the inner rectangle, then sprinkle the mozzarella evenly on top. Add the mushroom mixture and finish with the remaining 1/4 cup Parmesan.
9. Whisk together 1 egg and 1 tablespoon water and brush the pastry edges with the egg wash.
10. Bake for 20–25 minutes, until the edges are deep golden brown. Let cool slightly, then slice and serve warm or at room temperature.

Allow the tart to rest a few minutes before cutting so the filling sets slightly. Serve sliced as individual tartlets or as larger pieces alongside a simple salad.

Storage

The tart is best fresh and slightly warm. It can sit at room temperature for up to 2 hours before the crust softens. Refrigerate in an airtight container or wrapped tightly for up to 4 days; place a paper towel in the container to absorb excess moisture and help keep the crust from getting soggy.

To freeze, wrap individual slices tightly in plastic wrap or foil and place in a freezer-safe container. Thaw overnight in the refrigerator before reheating.

Make Ahead

Prepare the mushroom filling and cheese mixture ahead of time and store them in airtight containers in the refrigerator. When ready to bake, assemble the tart and continue from the scoring step.

Ingredients (serves about 9 appetizer portions)

• 1 sheet puff pastry, thawed
• 2 tablespoons olive oil, divided
• 1 shallot, thinly sliced
• 1 lb mixed mushrooms, thinly sliced
• 1/2 teaspoon salt, divided
• Black pepper to taste
• 1 clove garlic, minced
• 2 teaspoons fresh thyme (or 1 teaspoon dried)
• 1/2 cup ricotta cheese
• 1/2 cup Parmesan, shredded, divided
• 1/4 cup mozzarella
• 1 egg (for egg wash)

Tips & FAQs

Is this tart vegetarian? It can be made vegetarian by using hard cheeses made without animal rennet. To make it vegan, use vegan cheeses and a vegan puff pastry.

What if the mushroom filling is watery? Cook the mushrooms thoroughly so their liquid evaporates. Drain any remaining liquid before adding the mushrooms to the tart to avoid a soggy crust.

If you make this mushroom tart, try serving it with a simple kale-pomegranate or apple-pecan salad for a complete seasonal meal.