Step 1

Bring a large pot of cold water to a boil. Drop Brussels sprouts in the boiling water and cook until softened, 7 to 9 minutes, depending on their size. Strain and transfer to an ice bath to stop cooking. Strain once cooled and spread out on paper towels to dry. Pat the tops dry as well.

Step 2

Preheat the oven to 425 degrees F (220 degrees C).

Step 3

Place Brussels sprouts on a large baking sheet and smash with the bottom of a mason jar. Pat dry with a paper towel to soak up any additional liquid. Drizzle with olive oil and sprinkle generously with sea salt and pepper. Sprinkle pepper flakes over top, then shake the tray a bit to distribute the oil and spices.

Step 4

Bake in the preheated oven for 15 minutes. Gently flip sprouts and sprinkle with Pecorino Romano cheese. Return to the oven and bake until sprouts are soft and cheese is melted, 10 to 15 more minutes.

Step 5

Remove from the oven and set the tray on a wire cooling rack. Squeeze lemon over top, then transfer sprouts to a serving plate.