Heat the olive oil in a large paella pan or non-stick frying pan. Add the onion and fry for 5 minutes until softened. Add the garlic and fry for another 2 minutes. Add the pimenton and cook gently for 1 minute. Add the chopped tomatoes, bay leaves and dry pasta and stir until thoroughly coated with the oil. Pour in the stock, stir and bring to the boil. Simmer for 10 minutes until the pasta is al dente and the liquid has been absorbed. Season to taste.

Spoon into individual serving bowls and scatter over the chives to serve.