Tinned mussels are cheap, deeply savoury and almost entirely overlooked. The one rule is that they are already cooked: put them in at the start and you get rubber.
- Oil, dried onion three minutes, then garlic, paprika and chilli for twenty seconds.
- Tomatoes in, cooked down hard for 12 minutes until brick-coloured and thickened. This is where all the work is.
- Off the heat entirely, stir in the drained mussels. Ninety seconds in the residual heat is enough to warm them through.
- Vinegar over.
Keep a spoonful of the brine from the tin and add it if the sauce needs salt: it is far more interesting than salt on its own.
Serves 2 with bread or on polenta.