Salmon and Spinach Curry with Mango and Lime Pickle

• 450 g/1 lb fresh spinach
• 3 medium-sized ripe tomatoes

Wash the spinach and pick off any thick stalks. Bring a saucepan of water to the boil, add the spinach leaves and cook for 1-2 minutes, just until limp. Then turn them into a colander, run under cold water, drain well and chop finely.

Put the tomatoes into a bowl, cover with boiling water, then drain, peel and chop up small. Put the oil and butter into a fairly wide cast-iron casserole