Scrub and pare potatoes, but do not peel. Slice lengthwise into fourths. Butter a shallow microwave-safe baking dish. Dip potato slices first into the egg, then into the crumbs to coat. Place the slices in the baking dish. Top with any remaining crumbs. Dot with a tablespoon of butter, if desired. Microbake on 100% power 3-5 min, or until potato is tender and batter is set. If desired, top with the slice of cheese and mw 1 minute more to melt. Sprinkle with seasonings.