Preparation Melt butter in large nonstick skillet over medium-high heat. Add ham; sauté until ham is heated through and ends are curled, about 5 minutes. Stir in cream, syrup, and mustard. Simmer until sauce is slightly thickened and coats ham, about 3 minutes. Stir in 1/3 cup onions. Top toasted waffles with ham mixture. Sprinkle with remaining onions.
Preparation Melt butter in large nonstick skillet over medium-high heat. Add ham; sauté until ham is heated through and ends are curled, about 5 minutes. Stir in cream, syrup, and mustard. Simmer until sauce is slightly thickened and coats ham, about 3 minutes. Stir in 1/3 cup onions. Top toasted waffles with ham mixture. Sprinkle with remaining onions.