Skillet Macaroni and Beef

2 tablespoons vegetable oil
1/4 cup chopped onion
1/4 chopped green bell pepper
1 pound ground beef
2 cups cooked elbow macaroni
1 teaspoon prepared mustard
1 can condensed tomato soup
1/2 cup sour cream

Heat oil in a large skillet over moderate high heat. Add onions and pepper. Cook until light brown. Stir in ground beef and brown meat lightly, stirring frequently. Drain off fat. Stir in macaroni, mustard, tomato soup and sour cream. Blend well. Add salt to taste. Heat mixture to serving temperature.