Why You’ll Love This Recipe

Comforting layers of mushrooms, potatoes, and caramelized onions in every bite.
Versatile great as a main course with a side salad or scaled down for elegant canapés.
Makes use of wholesome, pantry-friendly ingredients that blend beautifully for rich, savory flavor.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

Fresh mushrooms (wild or cremini)
Baking potatoes
Sweet onions (such as Vidalia or yellow onion)
Refrigerated pie crust (store-bought or homemade)
Garlic
Fresh thyme (or dried thyme if preferred)
Olive oil or butter
Salt and black pepper
Grated cheese (optional for topping, such as Gruyère or Parmesan)
Egg (for egg wash, optional)

Directions

Preheat the oven. Prepare your baking dish (tart pan or baking sheet) by rolling out the crust and placing it in the pan; set aside.
Cook onion and mushrooms. In a skillet over medium heat, sauté sliced onions until they begin to caramelize, then add sliced mushrooms, garlic, thyme, salt, and pepper; cook until mushrooms are softened and golden.
Prepare potatoes. Thinly slice potatoes and par-cook (by steaming, boiling briefly, or microwaving) just until slightly tender but still firm.
Assemble the tart. Layer the potatoes, then the onion-mushroom mixture on top of the crust, or arrange in alternating patterns for visual flair. Brush the crust edges with egg wash if using. Optionally sprinkle with grated cheese over the filling.
Bake. Place in the preheated oven and bake until the crust is golden and filling is bubbling, about 25–35 minutes, depending on oven and thickness of ingredients.
Finish and serve. Remove the tart from the oven, let it rest for a few minutes, then slice and serve.

Servings and timing

Serves: About 6 people (depending on slice size)
Prep time: ~20 minutes; Cook time: ~35 minutes; Total time: ~55 minutes
(Based on typical tart recipes adjust if specific recipe includes different timing.)

Variations

Cheesy twist: Add thinly sliced Gruyère, Fontina, or sprinkle Parmesan over the top for extra richness.
Herb alternatives: Swap thyme for rosemary, sage, or a sprinkle of fresh parsley after baking.
Vegetable mix-in: Include thin slices of root veggies like sweet potato, parsnip, or even zucchini for variety.
Make it vegan: Use dairy-free butter or oil, skip the egg wash, and choose dairy-free cheese or omit cheese entirely.

Storage/Reheating

Storage: Keep leftovers covered with foil or in an airtight container in the refrigerator for up to 3 days.
Reheating: Preheat oven to about 180 °C (350 °F) and reheat the tart for 10–15 minutes to restore crispness. For single slices, a toaster oven or air fryer also works well.

FAQs

1. Can I use a gluten-free crust?

Yes simply swap your regular pie crust for a gluten-free one (store-bought or homemade). Make sure it’s sturdy enough to hold the filling without becoming soggy.

2. What mushrooms work best?

Wild mushrooms (shiitake, oyster, cremini, chanterelle) bring great flavor, but even button mushrooms work fine. Mix varieties if you like complexity.

3. Do I need to pre-cook the potatoes?

It’s recommended thinly slice and partially cook the potatoes until just tender, so they finish perfectly without the crust overbaking.

4. Can I prepare this tart ahead of time?

Absolutely assemble the tart and refrigerate (covered) for a few hours before baking. Let it come slightly to room temperature before placing in the oven.

5. What can I substitute for thyme?

Rosemary or sage work well or try adding a sprinkling of fresh parsley after baking for brightness.

6. Is this suitable for a brunch menu?

Definitely it pairs beautifully with salads, soups, or poached eggs for a hearty brunch option.

7. Can I make it dairy-free?

Yes use dairy-free butter or oil for sautéing, omit egg wash, and skip or replace cheese with dairy-free alternatives.

8. How do I get crisp crust and not soggy bottom?

Par-bake the crust for a few minutes before adding filling or make sure excess moisture in mushrooms and onions is cooked off.

9. Can I freeze leftovers?

You can freeze fully baked tart slices; wrap tightly and freeze for up to 1 month. Reheat directly from frozen in a 180 °C oven until warmed through.

10. Can I make mini tarts or tartlets?

Yes use a muffin tin or mini tart pans for individual portions. Adjust baking time accordingly check doneness around 20–25 minutes.

Conclusion

This Wild Mushroom, Potato & Onion Tart is a delightful blend of earthy, savory flavors wrapped in a crisp, buttery crust. Elegant yet simple, it’s perfect as a vegetarian main dish, starter, or brunch centerpiece. Easy to customize and even easier to enjoy, it makes for a cozy and satisfying kitchen creation.