This tomato and caramelised onion tart is the perfect summer food. Now the tomatoes are in season and they are perfectly ripe and super sweet.

Mixed tomatoes - flat lay

Preparing this tart is really easy and quick. If you don’t have enough time you can even buy ready-to-use pâte brisée (shortcrust pastry) or puff pastry. Then you only need a mix of tomatoes (I used mixed colours and shapes from “The tomato stall“, a farm on the Isle of Wight), onions, oil, salt, pepper and oregano. That’s it! The result a colourful tart, ready in no time and perfect for BBQ or picnics.

Tomato tart with caramelised onion ' flat lay

If you like this recipe maybe you could try my tomato soup perfect warm or cold, the amber tomato focaccia or a healthy and tasty spelt, shrimps and tomato salad

Tomato tart with caramelised onion

Prep Time:30 minutes
Cook Time:25-35 minutes


  • Pâte brisée
  • plain flour: 250 grams
  • unsalted butter cubed and cold: 125 grams
  • sea salt: 2,5 grams
  • water cold: 50-70 grams
  • Filling
  • cherry tomatoes: 350 grams
  • red onion finely sliced: 1
  • unsalted butter: 20 grams
  • caster sugar: 1 tsp
  • brown sugar: 2 tsp
  • beer or water: 2-3 tbsp
  • sea salt as needed
  • ground pepper to taste
  • extra virgin olive oil as needed
  • dry oregano


  1. To make the pâte brisée put flour, butter and salt into a large bowl. Use your fingertips to mix quickly until it resembles fine breadcrumbs. Slowly add the water a little at a time and mix without over kneading. Sometimes you don’t need to use all the water, just look at the consistency: it should be soft but not sticky and all the ingredients must be well combined. Roll into a ball then flatten the dough, wrap in cling film and set in the fridge for at least half an hour.
  2. Meanwhile prepare the caramelised onion. Melt the butter on low heat in a non-stick pan. Add the sliced onion and stir fry for a couple of minutes until it becomes slightly golden. Pour in the water, lower the heat and cover with a lid. Stir often to avoid the onion to burn and add a little water if needed. Once the onion looks soft add the sugar (both types), increase the heat and cook until all the liquid evaporates and the onion appears translucent, shiny and creamy. Let cool down completely.
  3. Take the pastry out of the fridge and roll it out 3 mm thick on a floured surface. Use it to line the tin, trim the edges and prick the bottom with a fork.Brisée pastry crust
  4. Spread the caramelised onion evenly on the pastry.
  5. Cut some tomatoes in halves and keep some whole. Arrange them on the onion layer, brush with a little oil, season with salt and pepper then sprinkle with oregano.Brisée crust with tomatoes
  6. Bake in the preheated oven to 190°C for about 25-35 minutes or until the tomatoes are soft and the edges of the tart golden.Tomato tart with onions