Heat the oil in a large flameproof casserole dish or saucepan with a tight-fitting lid over a medium–high heat. Add the chorizo and stir for 2 minutes. Add the onion and garlic and continue cooking for 3–5 minutes, stirring, until they are soft.
Add the rice to the dish and stir for 1 minute, then stir in the tomatoes with their juice, the tomato paste, corn, peas, bay leaf, stock, chilli flakes and sugar.
Slowly bring to the boil, stirring occasionally, then reduce the heat to low, cover the pan tightly with a lid and leave to simmer for 30–40 minutes until the rice is tender and all the liquid has been absorbed. Add a little more stock if the mixture becomes too dry before the rice is cooked. Season to taste.
Remove the dish from the heat and leave to stand for 5 minutes, with the pan covered. Heat the flour tortillas under a hot grill until warm. Serve the rice with coriander sprigs, lime wedges and the tortillas.