Vegetarian Casserole

In a large, heavy-based pan, warm the rapeseed oil over medium heat. Add the chopped onion and cook gently, stirring occasionally, for 5 to 10 minutes until it has softened and turned translucent.

Carefully remove and discard the thyme sprigs from the casserole. Stir in the cooked lentils, then bring the mixture back to a gentle simmer for a minute or two, just until they're warmed through.

Serve this casserole with wild and white basmati rice, a creamy mash, or quinoa.