Season chicken and pork with salt and pepper. Pan-fry in vegetable oil over medium heat until cooked, then set aside. Season shrimp with salt and pepper, then set aside. Boil clams until shell opens, then remove top and set aside. Fry garlic in olive oil until brown. Add onion, roasted rice, chicken stock, tomato ketchup, and water. Cover and bring to a boil. Reduce heat until the liquid evaporates and the rice is cooked. Garnish with remaining ingredients. Cover and simmer for a 10 to 15 minutes.