Spinach, leek and pea frittata

Method

1. Melt the butter and 2 tbsp oil over a low-medium heat in a deep, non-stick, medium (20-23cm) ovenproof frying pan. Slice the leeks into 1cm rounds. When the butter foams, add them and fry for about 7 minutes, stirring now and then, until soft and sweet.
2. Heat the oven to 180°C/160°C fan/gas 4. Add the spinach and peas to the leeks and increase the heat to medium. Cook for 2-3 minutes until the spinach is mostly wilted and the peas are bright green, then season.
3. Whisk the eggs and milk in a bowl and season. Add to the veg in the pan with the basil leaves (torn). Stir briefly to distribute evenly.
4. Bake for 20-25 minutes until firm. Cool for a few minutes, then put a serving plate on top and invert to remove from the pan. Dress the salad leaves with lemon juice and olive oil, season and serve with the frittata.