Boil eggs. Once cooled, cut up into small pieces, only using 1 yolk out of the 4 eggs. Chop onion into small chunks or salsa size. Add to chopped egg. Add mustard and seasoning. Seasoning can be changed to fit your tastes. Place mix over lettuce leaf, Wasa cracker or gluten free bread. You can also put in tomato or serve with cucumber, radishes, or another vegetable on the side.