Saute onion and green pepper until slightly softened; add tomato and saute for 1 minute more. In a medium-sized bowl, whisk together the eggs, milk, creamed corn and seasonings; add the sauteed vegetables. Lightly grease a 3 1/2-quart crock pot (or a souffle dish which fits in a larger crock pot) and pour the mixture in. Cook on HIGH 2 1/2 to 3 hours; add grated cheese to the top and cook until cheese is melted.