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Tomato tart with seeds in a puff pastry crust.

Roasted Tomato Tart with Onion Puff Pastry

This is the simplest tomato tart made with nothing but fresh heritage tomatoes, sticky onion jam, and crispy, flaky puff pastry scattered with onion seeds and thyme leaves. It's the perfect rustic tart for any time of day or night.
Course Dinner
Cuisine American, Italian
Keyword Tomato appetizer, Tomato tart with puff pastry, Vegetarian tomato tart
Prep Time 10 minutes
Cook Time 35 minutes
Total Time 45 minutes
Servings 12
Calories 131kcal
Author Debs


  • 1 sheet all-butter puff pastry
  • 1/4 - 1/3 cup onion jam
  • 1 lb heritage tomatoes mixed varieties
  • 1 egg beaten
  • 1 Tbsp mixed seeds poppy seeds, onion seeds, fennel seeds
  • 1 bunch thyme leaves picked
  • 1/2 bunch basil leaves chopped

Optional extras

  • Buratta or mozzarella
  • honey to drizzle
  • truffle oil


  • Preheat the oven to 400f.
  • Lay out the puff pastry on a piece of baking paper or a lined baking tray and spread the onion jam over the pastry leaving a 2 inch border around the edge.
  • Thinly slice the tomatoes and arrange over the top of the onion jam leaving the two inch border. Sprinkle generously with sea salt.
  • Brush the border of the pastry with the beaten egg and fold over the tomatoes creating a tart. Brush the outside with the pastry with the beaten egg and scatter with the mixed seeds.
  • Scatter the thyme leaves over the top of the tart and bake on a baking tray in the preheated oven for about 35 minutes.
  • Once cooked, place on a cooling rack until ready to serve. Drizzle with honey, olive oil or balsamic vinegar. Or all 3!