In a large saucepan or stockpot, cook sausage over medium-high heat, stirring frequently, until thoroughly cooked and no longer pink. Stir in tomatoes and green chiles; cover and cook 2 minutes. Stir in cheese and salsa, reduce heat to medium and cook uncovered until melted, stirring frequently. Stir in optional tomato and green onions, if desired. Serve hot with chips.