Add oil into a large lidded shallow casserole or paella pan on a medium heat. Add the garlic, onion, carrot, parsley stalks, chorizo, chicken and paprika and fry for 5 minutes, stirring regularly.
Add the capsicum and fry for a further 5 minutes. Stir in tomato paste and crumbled stock cube. Add the rice and stir for a few minutes. Pour in 750ml of boiling water. Add infused saffron and season with salt and pepper. Place the lid on and bring to the boil. Reduce heat and simmer for 15 minutes, stirring regularly and adding a splash of water if needed.
Stir in the peas and prawns and then embed mussels in the rice around the pan. Replace the lid and cook for a further 5 minutes or until heated through and mussel shells open. Season, top with chopped parsley leaves and serve with lemon wedges on the side.