Combine all ingredients except margarine and peaches in a bowl. Beat till smooth. Melt margarine in omelet pan; pour in egg mixture. Cook over low heat until the eggs begin to set. Loosen eggs with spatula from the sides of the pan. Tilt pan to allow uncooked egg mixture to spread to the sides. When center is firm, spoon peaches into the center of the omelet. Carefully fold two of the outer edges of the omelet into the center.
