Mix the dressing by combining the melted butter, mayonnaise, Dijon mustard, Worcestershire sauce, poppy seeds, honey, and dried onion in a small bowl.
Spread the dressing mixture over the top of the buns.
Cover the tray with two layers of aluminum foil and store in the freezer.
Bake for 20 minutes, until the buns are toasted and the cheese is melted.
Pull the sandwiches apart out of the tray or slice and serve.