In case two kinds of cheese and a pound of sausage aren't enough to transform a pot of mac and cheese, hopefully chipotle pepper will do the trick.
Preheat oven to 350°F. Lightly grease a 2- to 2 1/2-quart casserole; set aside. Cook pasta according to package directions; drain. Return to pan.
Meanwhile, in a medium saucepan melt butter over medium heat. Stir in flour; cook and stir for 1 minute. Gradually stir in evaporated milk and milk. Cook and stir until slightly thickened and bubbly. Remove from heat. Stir in 1 cup of the Monterey Jack cheese, 1 cup of the cheddar cheese, the chipotle pepper, and salt. Stir cheese mixture into cooked pasta. Stir in cooked sausage.
Transfer mixture to the prepared casserole. Sprinkle with the remaining 1/2 cup Monterey Jack cheese and the remaining 1/2 cup cheddar cheese. Place casserole on a baking sheet. Bake, covered, about 30 minutes or until bubbly. Let stand for 10 minutes before serving.