Makes one 25cm tart, to serve 8-12

75g Puy lentils

200g pack baby spinach leaves

2 tbsps extra virgin olive oil

2 large leeks, sliced thinly

50g butter

2 free-range eggs

3 yolks

1 x 284ml pot single cream

150ml milk

150g gruyère cheese, grated

Sea salt and freshly ground pepper

Pastry

200g plain flour

1/2 tsp sea salt

1 tsp ground paprika or mustard powder

75g chilled and diced butter

25g vegetable shortening

A trickle of ice cold water

1. First, make up the pastry. Sift the flour, salt, paprika or mustard into a food processor then add the diced butter and shortening. Process until the mixture looks like fine crumbs, then trickle in just enough water to form a dough.

2. Turn the mixture out on to a lightly floured board and knead lightly to a ball. Cover with cling film and chill for 15 minutes.

3. Boil the lentils according to pack instructions. Drain, season and toss with the olive oil. Cool.

4. On a lightly floured surface, roll out the pastry to a circle large enough to line a 25cm loose-bottomed flan tin, bringing the dough right up the sides and pressing well into the sides. Do not trim the sides, and pinch any gaps together. Prick the base with a fork and line with non-stick baking paper and baking beans. Chill for at least half an hour while you make the filling.

5. Cook the spinach in a pan with a little oil. Cool, squeeze out as much liquid as possible then chop. Set aside.

6. Stir-fry the leek in the butter with 2 tablespoons water for about 5 minutes until softened. Season well. Mix with the spinach and lentils. Cool.

7. Beat the eggs and yolks then mix in the cream and milk. Season well.

8. Meanwhile, preheat the oven to 200C, Gas 6. Place the flan tin on a baking sheet and bake blind for 12 minutes. Carefully remove the paper and baking beans and return the flan to the oven for another 5 minutes. Remove and turn the oven down to 180C, Gas 4.

9. Now, using a sharp knife, trim the soft edges so the pastry is flush with the top of the tin. This little trick ensures the pastry has cooked without shrinking back.

10. Spoon the vegetables into the case and sprinkle over the cheese. Slowly pour in the egg and cream mixture. Return the flan to the oven and bake for 35-40 minutes until risen and golden-brown. Allow to cool for 15 minutes before pushing up out of the flan tin. Nicest served warm but not hot.

Times Recommends

• Three recipes for Dover sole
• The perfect summer wine list
• Urban Farmer: courgette ideas