Step 1

Thaw the frozen broccoli, then chop it into smaller pieces. Add the chopped broccoli to a large bowl along with the cooked rice and about 1.5 cups of the shredded cheese (save the last ½ cup for topping the casserole).

Step 2

Begin to preheat the oven to 350ºF. Finely dice the onion and mince the garlic.

Step 3

Add the butter, onion, and garlic to a small saucepot and cook over medium heat until the onions are soft and translucent (2-3 minutes). Add the flour and stir until a paste forms. Continue to stir and cook the paste for about two minutes, or just until it turns a light golden brown.

Step 4

Whisk the milk into the butter and flour mixture. Continue to whisk the mixture as it heats, allowing it to reach a simmer, at which point it will thicken to the consistency of heavy cream. Remove the sauce from the heat.

Step 5

Season the sauce with the salt, smoked paprika, cayenne, and pepper. Taste the sauce and add more seasoning if desired. The sauce should be heavily seasoned because it will be spread out over the broccoli and rice, which contain no seasoning of their own.

Step 6

Pour the sauce over the rice, broccoli, and cheese, and stir until everything is evenly coated in sauce. Spread the casserole mixture evenly into a 9x9 inch casserole dish. Top with the remaining shredded cheddar.

Step 7

Bake the casserole for about 35 minutes, or until the cheese on top is melted and is slightly browned around the edges. Divide into six portions and serve.