Brown ground beef in large skillet over medium-high heat until thoroughly cooked, stirring frequently. Drain.
Add refried beans, tomato sauce and salsa; mix well. Cook and stir 4 to 5 minutes or until thoroughly heated and bubbly.
In small bowl, combine sour cream and cheese; mix well. Spoon over beef mixture. Cover; cook over low heat for 3 to 4 minutes or until thoroughly heated. Remove from heat. Top with lettuce and tomatoes. Serve with tortilla chips for dipping.