FOR each serving: Spread 1 bread slice with 1 Tbsp. dressing; spread second bread slice with 1 Tbsp. mustard. Top 1 of the bread slices with 2 oz. ham, 2 Tbsp. cheese and 3 tomato slices; cover with remaining bread slice.
PREHEAT flat top griddle at 350°F. Add sandwich; cook 2 minutes on each side or until golden brown on both sides. Cut diagonally in half to serve.