Ingredients
For the Filling
- 3 tbsp olive oil
- 2 large onions, halved and finely sliced
- 1 garlic clove, crushed
- 2 tbsp Dijon mustard
- 1/2 cup (100g) Gruyere cheese, grated
- 1/4 cup (50g) Grana Padano, grated
- 1 & 2/3 cup (300g) cherry tomatoes, halved (use a variety of shapes and colors, if you like)
For the Pastry
- 2 & 1/2 cups (350g) all purpose flour
- 5 fl oz (150ml) olive oil
- 1 tsp salt
- Cold water
Directions
Step 1
To make the pastry, mix the flour with 1 tsp salt then stir in the olive oil and just enough water so it comes together as a dough (you’ll need about 4-5 tbsp). Roll out the pastry between 2 sheets of baking paper until it’s large enough to line an 11 inch round tart pan. Trim the edge and chill while you make the filling.
Step 2
Heat 3 tbsp olive oil in a large pan, add the onions and a good pinch of salt. Sauté very gently over medium-low heat for 20-30 minutes or until meltingly soft and golden. Add the garlic and cook for another couple of minutes. Cool and mix in the mustard and cheeses.
Step 3
Heat the oven to 350 degrees F. Bake the tart shell for 20 minutes then take out and cool.
Step 4
Spread the cheesy onions over the base of the tart. Place the tomatoes on top in a single layer, cut-side up, and season with salt and pepper. Put the tart back in the oven for another 20-25 minutes or until the pastry is crisp and the tomatoes are slightly golden. Serve just-warm.
Adapted from Olive Magazine.