Cook elbow macaroni according to package directions. Drain; rinse with cold water; drain again.
Meanwhile, in a 12-inch skillet over medium-high heat, cook sausages until well-browned on all sides and cooked through, turning frequently, about 15 minutes. Remove sausages to cutting board.
Add green pepper and onion to drippings remaining in skillet; cook over medium-high heat until tender, about 8 minutes, stirring occasionally. With a slotted spoon, remove to a large bowl. When sausages are cool enough to handle, cut into 1/2-inch slices and place in bowl with vegetables.
Preheat oven to 375°F. Grease a 12x8-inch baking dish. Melt butter in a 2-quart saucepan over medium heat. Stir in flour and cook 1 minute. Gradually whisk in milk. Heat to boiling, stirring frequently. Remove from heat and stir in cheeses, TABASCO® Sauce, and salt until cheeses melt, stirring frequently.
Add cheese sauce to bowl with sausage mixture along with macaroni and mix well. Spoon into prepared baking dish and bake 20 to 25 minutes or until mixture is hot and bubbly.
Makes 6 servings.