3 slices bacon
1 head cauliflower (about 2 pounds), cut into bite-size pieces
½ teaspoon ground pepper
¼ teaspoon salt
1 ¼ cups shredded sharp Cheddar cheese, divided
⅔ cup sour cream
4 scallions, sliced, divided
Gather all the ingredients. Preheat oven to 425 degrees F.
Place bacon in a large nonstick skillet over medium heat; cook until crisp, 6 to 8 minutes. Transfer to a paper-towel-lined plate and let cool. (Reserve the drippings in the pan.)
Combine cauliflower, 1/2 teaspoon pepper, 1/4 teaspoon salt and the bacon drippings in a 9-by-13-inch baking dish. Roast, stirring twice, until tender, about 35 minutes.
Meanwhile, combine 1 cup cheese, 2/3 cup sour cream and half the scallions in a small bowl.
When the cauliflower is tender, stir the cheese mixture into the cauliflower in the pan. Sprinkle with the remaining 1/4 cup cheese. Bake until hot, 5 to 7 minutes more.
Chop the cooled bacon.
Sprinkle the hot casserole with the bacon and the remaining scallions.