Sausage and cider casserole

Method

1. Heat 1 tbsp olive oil in a large, lidded flameproof casserole or heavy based pan over a medium-high heat. Add the sausages and cook for 6-8 minutes, turning every few minutes, until browned. Transfer to a plate and set aside.
2. Add the remaining oil to the pan with the onion and leeks. Stir in a pinch of salt and fry for 10 minutes. Add the vinegar and sugar and cook for 2-3 minutes more, stirring until the liquid has evaporated and the onions/leeks are sticky and caramelised.
3. Add the garlic, cook for another minute, then pour in the cider. Bubble for 2-3 minutes over a high heat, then add the stock to the pan along with the sausages. Bring everything up to a simmer, then turn down the heat and cook for 20-25 minutes, or until the sausages are cooked through and the sauce is rich and thickened.
4. Stir in the mustard and salt and pepper to taste. Add the spinach and cover with a lid for 2-3 minutes until wilted, then stir it in. Serve two-thirds of the casserole with mash, rice or crusty bread.