This quick and easy crispy cheesy broccoli gratin features crispy, caramelized broccoli florets topped with a panko cheddar parmesan mixture that's out of this world… Have it on your dinner table in under 20 minutes!
Place a rimmed sheet pan on the middle rack of your oven and preheat to 400 degrees.
Toss the broccoli florets with the olive oil and salt in a medium-size bowl. Turn the broccoli out onto the hot sheet pan (it should sizzle!) and roast until the bottom of the florets are nicely browned, about 15 minutes.
Meanwhile, combine the butter and garlic in a ramekin and place it in the oven until the butter melts, about 5 minutes.
Place the bread crumbs in a medium-size bowl, add the butter-garlic mixture, and toss with a fork. Add the cheddar and Parmesan cheese and toss to combine.
Remove the sheet pan from the oven and sprinkle the broccoli with the cheesy bread crumb mixture. Turn the broiler to high and place the sheet pan on the upper rack. Broil until the cheese is melted and browned, 1-2 minutes. Watch the bread crumbs closely, as broiler intensities vary and you don't want them to burn!
Remove from the oven, and transfer to a platter, making sure to scrape up all of the crispy, crunchy cheesy bits. Serve warm.