Tarte à la Tomate

Buttery pastry topped with creamy mustard-scented base and juicy tomatoes roasted until sweet, jammy, and lightly blistered.

Ingredients

• 1 sheet puff pastry (about 250 g / 9 oz), thawed if frozen
• 5–6 medium ripe tomatoes (about 900 g / 2 lb), sliced 6–8 mm (1/4–1/3 in) thick
• 2 tbsp Dijon mustard
• 120 g (1 cup) grated Gruyère (or Emmental)
• 2 tbsp extra-virgin olive oil
• 1 tsp fresh thyme leaves (or 1/2 tsp dried thyme)
• 1/2 tsp kosher salt, plus more as needed
• 1/4 tsp black pepper
• 1 small garlic clove, finely grated (optional, pantry staple)
• 1 tsp balsamic vinegar (optional, pantry staple)
• 1 egg, beaten with 1 tsp water (for egg wash)

Method

• 1

  Step 1: Preheat & prep tray

  Preheat oven to **200°C / 400°F (180°C fan)**. Line a baking tray with parchment paper.

• 2

  Step 2: Drain the tomatoes (prevents soggy tart)

  Lay tomato slices on a double layer of paper towels. Sprinkle lightly with **1/2 tsp salt** and let sit **10 minutes**. Blot the tops well with more paper towel until the surface looks dry (this step is the difference between crisp and soggy).

• 3

  Step 3: Prepare the pastry base

  Place puff pastry on the lined tray. Score a border **1.5 cm / 1/2 in** from the edge (don’t cut through), then prick the center all over with a fork (this keeps the middle flatter). Chill the tray in the fridge **5 minutes** if the pastry feels soft.

• 4

  Step 4: Build the flavour base

  Spread **Dijon mustard** evenly over the pricked center. Sprinkle over the **Gruyère** (this acts as a tasty moisture barrier). If using, mix the **garlic** into the mustard before spreading for a subtle savoury lift.

• 5

  Step 5: Arrange tomatoes

  Overlap tomato slices over the cheese in tight rows or concentric circles, keeping them within the border. Drizzle with **olive oil**, scatter over **thyme**, and finish with **pepper**.

• 6

  Step 6: Egg wash & bake

  Brush the border with egg wash (avoid getting egg wash on the tomatoes). Bake **35–40 minutes**, rotating the tray at the 25-minute mark, until the border is **deep golden and crisp** and the tomatoes look **slightly blistered with some browned edges**.

• 7

  Step 7: Finish & serve

  Let rest **10 minutes** (this helps the filling set). If using, drizzle lightly with **balsamic** right before slicing. Serve warm or at room temperature.

Tips

• **Tomato choice matters**: Use ripe but firm tomatoes. Very watery tomatoes can be used—just be extra thorough blotting, and don’t skip salting/draining.
• **Cheese swaps**: Emmental, Comté, or a mix of mozzarella + a little Parmesan works well.
• **No Dijon?** Use a thin layer of wholegrain mustard. If you must skip mustard, increase cheese slightly and add a pinch more thyme and pepper.
• **Crispier base insurance**: Bake the pastry **10 minutes** after scoring/pricking (no toppings), then add mustard/cheese/tomatoes and finish baking **25–30 minutes**.
• **To serve**: Great with a simple green salad dressed with olive oil, vinegar/lemon, salt and pepper.
• **Storage**: Keeps **3 days** refrigerated. Re-crisp on a tray in a **190°C / 375°F** oven for **8–12 minutes** (microwave will soften the pastry).

Nutrition (per serving, estimate)