Soak the saffron in 2 Tbsp boiling water. Place the chicken, cumin, chili powder, salt and pepper in a bowl and toss to coat. Heat the oil in a large skillet over medium heat. Add the chicken and cook until just cooked through, remove from pan and set aside. Add the onion, green pepper and garlic to the skillet and cook 3-4 minutes. Add the tomatoes, rice, stock, paprika and saffron. Season with salt and pepper and bring to a boil. Reduce the heat to medium-low and gently simmer for 20 minutes, until the rice is firm/tender and still slightly wet (add a little additional stock if not). Nestle the chicken, prawns, scallops, mussels, sausage and olives into the rice. Cover and cook for 5-8 minutes, or until the prawns and scallops are cooked, the mussels open, and the rice is tender. Sprinkle with parsley; serve with lemon wedges.