Serves 4-6

• 1 tbsp olive oil
• 10g butter
• 2 leeks, trimmed and sliced
• 1 onion, finely sliced
• 300 ml semi skimmed milk
• 3 eggs
• 1 tbsp mustard
• Large handful chives, chopped
• 100g frozen peas
• Ready rolled puff pastry sheet
• 50g cheddar cheese, grated

1. Heat oven to 180C.
2. Heat oil and butter in a pan, add the leeks and onion and cook for 5 minutes, until slightly soft.
3. In a bowl, whisk together the milk and eggs and stir in the mustard and chives.
4. Grease a long, thin baking tray (no need for greasing if you are using stoneware) and line it with the puff pastry sheet, making sure it goes up the sides.
5. Sprinkle the leeks and onions over the pastry and spread the peas on top.
6. Pour over the egg mixture and sprinkle the cheese over the top.
7. Bake in the oven for 30 mins until pastry is golden and the tart has set.

You can use a bunch of spring onions rather than onion if you prefer.

This can be eaten hot or cold. It keeps well for the next day if you have any left.