Looking for an easy and delicious vegetarian dish? This Mushroom Tart (Tarte Fine aux Champignons) is a French classic that's sure to impress. The rich, buttery puff pastry topped with sautéed Swiss brown mushrooms, Gruyère cheese, and fresh thyme is as simple as it is flavorful.

Baked to crispy perfection, this tart is a delightful choice for a light meal or starter, and it pairs wonderfully with a fresh salad on the side.

Ingredients

1. Base Ingredients

• Puff pastry – 1 square sheet (25 cm/10 inches), barely thawed

• Extra pure olive oil – 1 tbsp

• Unsalted butter – 2 tbsp

• Swiss brown mushrooms – 400g (14 oz), sliced into 0.5 cm pieces

• Cooking salt – ½ tsp (use less for table salt)

• Black pepper – ¼ tsp

• Gruyère cheese – 1 ½ cups, tightly packed, grated

• Unsalted butter (melted) – 2 tsp for brushing

2. Toppings

• Fresh thyme leaves – 1 ½ tsp

• Sea salt flakes – a pinch

• Truffle oil or extra pure olive oil – for drizzling (optional but recommended)

Instructions

1. Preheat and Prepare

• Preheat the oven to 210°C / 410°F (or 190°C fan).

• Place a baking tray in the oven to heat up.

2. Sauté the Mushrooms

• Heat the olive oil and butter in a frying pan over medium-high heat.

• Add the mushrooms, salt, and pepper, then sauté for about 5 minutes until soft and reduced.

• Transfer mushrooms to a colander over a bowl to drain excess liquid.

3. Prepare the Base

• Place a sheet of baking paper on your work surface and lay the puff pastry on top.

• Fold the edges inward to create a 1 cm (0.4") border and brush with melted butter.

4. Assemble the Tart

• Spread the Gruyère cheese evenly over the pastry base.

• Top with the sautéed mushrooms, spreading them out evenly.

5. Bake the Tart

• Lift the baking paper and carefully transfer the tart onto the hot tray in the oven.

• Bake for about 30 minutes, or until the pastry is golden and crispy, with the cheese melted.

6. Finish and Serve

• Once baked, sprinkle the tart with fresh thyme leaves and sea salt flakes.

• Drizzle with truffle oil or a good-quality extra pure olive oil for an extra touch of flavor (optional but highly recommended).

• Slice and serve warm with a fresh salad for a perfect light meal.

Recipe Notes

1. Puff Pastry

- Puff pastry sheets are commonly sold in **25 cm / 10" squares** in Australia. If your sheet is larger, trim it down; if smaller, press pieces together to form a larger sheet.

2. Cheese Options

• Gruyère is ideal for this recipe, offering a great flavor and smooth melt. If you can't find it, Comté, Swiss, or Emmental are good substitutes. You can also use mild melting cheeses like Cheddar or Monterey Jack.

3. Mushroom Variations

• Swiss brown mushrooms (cremini) work best due to their deep flavor. You can also use Portobello mushrooms if sliced thinly. Avoid irregular mushrooms that don't slice evenly.

4. Truffle Oil

• Truffle oil adds a luxurious touch to this tart. If you don't have it, use high-quality extra pure olive oil instead for a wonderful flavor.

Serving Suggestions

This tart makes an excellent lunch, light dinner, or starter. Pair it with a simple green salad or roasted vegetables to complete the meal. You can also serve it as part of a tapas-style spread.

Conclusion

This Mushroom Tart is the epitome of simple elegance. With minimal ingredients and a few easy steps, you can create a dish that's not only visually appealing but also bursting with rich, earthy flavors. Whether you're entertaining or just enjoying a quiet meal at home, this tart is sure to impress everyone at the table.