Preheat the oven to 350°F.
Using a sharp knife, finely chop the 10 ounces of frozen broccoli into very small pieces.
Then, steam the broccoli in the microwave or stovetop until soft, about 2-3 minutes and then set aside.
Next in a large pot, boil the 2 bags of rice on the stovetop according to the package directions. Once done, drain and set aside.
Chop the 8 ounce Velveeta cheese block into large cubes and put them in a heavy bottom saucepan. Add in ½ a can of cream of mushroom soup, 1 cup of whole milk, 2 teaspoons of butter, ¾ teaspoon of salt and ½ teaspoon of pepper.
On medium-low heat, stir the ingredients and whisk continuously until all the ingredients are melted and the sauce starts to slightly thicken, about 5-7 minutes.
Reserve ½ cup of the melted Velveeta cheese sauce in a small dish and set it aside.
Add the cooked chopped broccoli, cooked rice, and melted Velveeta cheese sauce to a large bowl.
Using a large spoon, mix to combine.
Pour the broccoli casserole mixture into the oven safe dish.
Bake for 20 minutes, or until slightly golden brown on top. When done, stir in the reserved cheese sauce.
Remove the dish from the oven and let it cool for 3-5 minutes before serving.