Start by washing your broccoli heads thoroughly under cold water. Cut the florets away from the main thick stalk, aiming for medium-sized pieces that are roughly the same size. Place your broccoli florets into a steamer basket over a pot of boiling water. Cover the pot and let them steam for about five to seven minutes.
Once they are tender, remove them from the heat and let them sit for a minute so the excess steam can escape.
Spread the steamed broccoli out on a clean kitchen towel or a layer of paper towels. Gently pat the tops of the florets to remove as much moisture as possible.
Preheat your oven to 425°F while you get your baking sheet ready. Line a large rimmed baking sheet with parchment paper or a silicone baking mat.
Place the dried broccoli florets onto the prepared baking sheet, leaving plenty of space between each one. Take a heavy glass or a small bowl with a flat bottom and press down firmly on each floret. You want to flatten them out until they are about half an inch thick.
In a small bowl, whisk together the olive oil, garlic powder, onion powder, salt, black pepper, and red pepper flakes. Use a pastry brush or a small spoon to drizzle this seasoned oil over each smashed floret.
Sprinkle the freshly grated Parmesan cheese generously over the top of each piece of broccoli. Try to get a little bit of cheese on the parchment paper right around the edges of the broccoli.
Slide the baking sheet into the hot oven and bake for 15 to 20 minutes. You are looking for the cheese to turn a deep golden brown and the edges of the broccoli florets to look dark and crispy. As soon as you pull the tray out of the oven, drizzle the fresh lemon juice over the hot broccoli.
