In medium skillet, cook sausage and onion over medium high heat, 5 to 6 minutes or until meat is thoroughly cooked; drain. Stir in beans; cook 1 to 2 minutes, until heated through. Set aside.

In a small bowl, beat 2 eggs until frothy. Melt 1 teaspoon butter in 8-inch nonstick skillet over medium-high heat. Add eggs to skillet; cook, stirring quickly until eggs begin to thicken. With a rubber spatula, pull edges of omelet into the center, allowing uncooked eggs to flow to edges of pan and underneath omelet. Cook until just set, about 1 minute. Spoon 1/3 cup of the bean mixture, 3 tablespoons tomato and 2 tablespoons cheese over one half of omelet; fold other half of omelet over filling. Place omelet on a plate. Repeat cooking process with remaining butter, eggs and filling ingredients.

Serving suggestion: If desired, top with chopped cilantro, additional shredded cheese and sour cream. Serve with warm flour tortillas and fresh fruit for a delicious breakfast.