Heat oven to 350°F. Cook and drain pasta as directed on package, adding broccoli 5 minutes before pasta is done cooking.
Return cooked pasta and broccoli to pan; stir in tuna, soup and milk. Spoon into ungreased 8-inch square (2-quart) glass baking dish.
Bake 15 minutes. Sprinkle with bagel chips. Bake 10 to 15 minutes longer or until bagel chips are lightly browned and casserole is hot.