Brown sausage in olive oil.

Sauté onion, green peppers and mushrooms in olive oil.

Spray crockpot evenly with cooking oil. Layer the ingredients as follows: potatoes, sausage, bread, onion/green pepper/mushroom mixture and cheese; potatoes, sausage, bread, onion/green pepper/mushroom mixture and cheese.

Beat eggs, milk, mustard, salt and pepper together. Pour over layers.

Cook on low for 8-10 hours