Melt butter in a small pan. Add onions and cook until translucent
Combine evaporated milk and soup in a medium pot and heat over medium high heat. Add in Velveeta cheese and stir until the mixture is smooth and combined well.
In a 2 quart baking dish, stir together rice, onions and butter, cheese sauce and broccoli. Stir to combine. Top with cracker crumbs.
Bake at 375 degrees for 45 minutes.