Tomato Tart with Swiss Cheese and Rosemary

Begin by cooking the onions in 2 tablespoons of olive oil and some seasoning over a gently heat in a medium-sized pan or casserole until soft and melting, which will take about 30 minutes.

Meanwhile roughly chop the tomatoes and drain them really well in a sieve. Now add the tomatoes, chilli, sugar, garlic and rosemary to the onions and cook over a gentle heat (stirring from time to time) until everything has reduced and become really thick. 

This will take about 45 minutes and at the end of the cooking time you should have no spare liquid in the pan, then remove the pan from the heat, cool and add some seasoning. While the tomato filling cools, roll the pastry to a 28cm round and line the flan dish, pushing the pastry well into the edges, then trim away the pastry hanging over the side with a small sharp knife and prick the base.

Now spread the mustard over the base using the back of the tablespoon and then cut each of the slices of Emmental into four and spread them out evenly across the base of the tart.

Pre-heat the oven to 200C/Gas mark 6 and place the baking tray in the oven.

When the tomato filling has cooled, spread it evenly over the cheese and drizzle with 1 tablespoon of the extra virgin olive oil.  Place it on the preheated baking tray and bake on the centre shelf for 30 minutes until the pastry is crisp and deep golden brown.

When it comes out of the oven, drizzle with the remaining oil and serve cut into wedges.

TO FREEZE: When its absolutely cold, wrap it in double foil.  Then reheat on a baking tray at the same temperature for 10 minutes before serving.