Spray heated skillet with non stick spray, add onions and a dash of salt. Cook for approximately 10 minutes, until caramelized. Remove from heat.
Stir mustard and honey together. Spread 4 slices of bread with mustard mixture, then layer with ham, onions, and cheese; top with remaining slices of bread.
Place in sandwich press or indoor grill and cook until cheese has melted.
Serve with steamed edamame and sliced pears on the side.