Open up the bagel and spread on the lite mayonnaise and a Dijon mustard on one side.
Stack ham, cheese, red onion, and pineapple on the other side of the bagel.
Top with the side of the bagel that has the mayo and mustard and grill for 5 minutes on each side or you can bake the sandwiches in a 350°F oven for 7 minutes or until cheese is melted.