Yields 6 servings
Adapted from America’s Test Kitchen
1 Pound broccoli 1-in florets, stalks chopped
1 Pound brussels sprouts, cut in quarters (small if large ones)
2 Tbls butter, unsalted
1 Medium shallots minced
2 to 4 Cloves garlic, fresh minced
1 Tbls flour, all-purpose
3/4 Cups cream, heavy
3/4 Cups stock, vegetable
1 Pinch nutmeg, fresh grated
1 Pinch pepper, cayenne
¼ tsp salt
1/8 tsp pepper, black, ground
1 tsp thyme leaves, fresh
4 Ounce(wt)s cheese, cheddar sharp grated
¾ cup breadcrumbs, panko
Butter-flavored cooking spray
Adjust oven rack to middle position; heat oven to 450 degrees. Microwave the broccoli and sprouts on power 7 for 7 minutes or until exterior is tender but interior is still slightly crunchy. Set aside while preparing sauce.
Heat butter in large skillet over medium heat; when foam subsides, add shallot and cook until softened, about 2 minutes. Add garlic and cook until fragrant, about 30 seconds; stir in flour until combined, about 1 minute. Whisk in cream and broth; bring to boil. Stir in nutmeg, cayenne, salt, pepper, thyme, and two-thirds cheese until incorporated. Off heat, gently stir in broccoli and sprouts until evenly combined. Transfer mixture to 11- by 7-inch (2-quart) gratin dish. Sprinkle remaining one-third cheese evenly over surface, then sprinkle evenly with breadcrumbs. Spray top with cooking spray.
Bake until golden brown and sauce is bubbling around edges, 15 to 20 minutes. Serve immediately.