Put 1 tbsp oil in a large pan with a tight-fitting lid. Add the chorizo and fry until crisp, then scoop out with a slotted spoon onto a plate and add the onion, garlic, paprika, chilli and thyme sprigs to the pan. Cook over a low heat until softened, then up the heat again, return the chorizo to the pan and add the wine, chopped tomatoes, tomato purée, a pinch of sugar, plenty of pepper and a tiny bit of salt. Simmer for 2 minutes.
Stir in the mussels, cover with a lid and steam for 3-4 minutes, shaking the pan a couple of times, until the mussels have opened. Divide between bowls and serve with fries or crusty bread.