Spray a large non-stick frying pan with low-calorie cooking spray and place over medium-low heat.
Add the onions, garlic, chorizo, and carrot and stir-fry for 6-8 minutes, or until softened.
Add the tomatoes and cook for 2-3 minutes.
Stir in the paella rice and cook for a further 2-3 minutes.
Add the chicken, tomato purée, paprika, and saffron.
Pour in enough water to just cover the rice, and bring to the boil. Reduce the heat to medium-low, cover and simmer for 15-20 minutes, stirring occasionally.
When only a little water remains in the pan, stir in the peppers and peas. Cook for a further 5-6 minutes or until the rice is just tender and the chicken is cooked through. Add a little boiling water if it gets too dry.
Season lightly to taste and scatter over the parsley.
Divide between 4 bowls and serve with lemon wedges and finely chopped parsley.