Chicken and chorizo paella

Name: Chicken and chorizo paella
Ingredients: 1–2 tbsp oil; 12 whole chicken pieces (legs or thighs), on the bone; 1 chorizo sausage, sliced into 3mm/⅛in thick slices; 1 large onion, finely chopped; 3 garlic cloves, crushed; 2 red peppers, seeds removed, sliced; 2–3 red chillies, seeds removed, chopped; 2 tsp smoked paprika; 1.5 litres/2½ pints chicken stock; 400g/14oz paella rice; 12 mussels or clams, (optional) cleaned, open and damaged shells discarded; Handful parsley, roughly chopped