Saute green pepper and onions in 1 tablespoon margarine over medium-high heat until tender. Combine corn, eggs, cheese, and green pepper mixture in a large bowl; stir well with a wire whisk.
Combine flour and next 3 ingredients; add to corn mixture. Stir in remaining 1 tablespoon margarine, half-and-half, and remaining ingredients. Pour mixture into a lightly greased shallow 1 1/2-quart baking dish. Place dish in a 13- x 9- x 2-inch pan; pour hot water into pan to a depth of 1 inch. Bake, uncovered, at 325° for 1 hour or until a knife inserted in center comes out clean.