Zippy Egg Casserole

Ingredients

• 1 lb pork sausage
• 1 (5 1/2 ounce) package seasoned croutons
• 1 1/2 cups shredded cheddar cheese
• 1 cup shredded swiss cheese
• 1 cup shredded monterey jack pepper cheese
• 8 eggs
• 1 pint half-and-half
• 1 1/2 cups milk
• 1 1/2 teaspoons dry mustard
• 1 tablespoon minced onion
• salt and pepper