Preheat oven to 350 degrees F. Grease the inside of a 4-quart casserole dish.
Fill a large pot with water and bring to a boil. Once boiling, add 1 teaspoon salt and the broccoli. Allow it to boil for 4 minutes. The broccoli should still be a bit firm as it will continue to cook the casserole.
Drain the broccoli and set aside.
Sauce
Melt the butter in a large pot over medium heat.
Whisk in flour and cook for 2-3 minutes, stirring constantly.
Stir in the garlic powder, onion powder, dry mustard, salt, and pepper. Cook for another minute, stirring constantly.
Slowly whisk in milk and stir until there are no lumps. Bring to a simmer for 5 minutes, until thickened.
Sti in Havarti and Colby-Jack cheese. Keep stirring until the cheese is melted.
Casserole
Add broccoli, ham, and cooked rice to the sauce and stir to combine.
Pour the mixture into your prepared casserole dish and spread evenly.
Top with remaining cheese and place into the oven to bake for 20 minutes.
While the casserole is baking, combine the melted butter and Panko bread crumbs in a small bowl.
Remove the casserole from the oven and top with the bread crumbs. Let rest 5 minutes before serving.
Notes
If you don’t have rice already cooked, you can cook it while the broccoli and sauce are cooking. Remember this recipe calls for 3 cups COOKED rice. If you’re making it for this recipe be sure to measure it after it has cooked.