Preheat oven to 350°F. Cook macaroni to al dente according to package
instructions and drain.
Meanwhile, melt butter in a large heavy saucepan over medium-low heat.
Stir in flour, salt, and pepper and cook 1 to 2 minutes. Whisk in milk and
cook over medium heat until thickened and bubbly, stirring constantly.
Reduce heat to low and stir in cheeses until melted. Add TABASCO
Buffalo Style Sauce, chicken, green onion, macaroni, and additional salt
and pepper to taste; mix well.
Spoon into an ungreased 2-quart casserole dish and top with bread
crumbs. Bake for 25 to 30 minutes or until heated to an internal
temperature of 165°F.