Slice florets off broccoli heads, then cut into large bite-sized chunks.
Use a vegetable peeler to peel the tough broccoli stalks, after trimming the end off the bottom.
Slice the thin broccoli stems and peeled stalks into ¼-inch thick coins.
Add the broccoli florets, stems, stalks, and leaves to a large mixing bowl.
Drizzle olive oil over the broccoli in the bowl. Add salt, crushed red pepper (if using), and a few grinds of black pepper. Toss with your hands until the oil and spices are evenly distributed.
Pour the contents of the bowl onto the foil-lined sheet pan and spread out until you have a single layer of vegetables.
Put baking sheet into the oven.
After 10 minutes, stir broccoli.
Roast for another 5 minutes and stir again—your broccoli should just be starting to brown.
Roast for an additional 3-5 minutes, until the broccoli edges are crispy and the broccoli is fork tender.
Notes
Keep in mind that your mileage may vary when roasting. Ovens can run hot or less hot, and sheet pans can be more or less heat-conductive. All that is to say, try this recipe with your oven and your pan, and then adjust. You may need more or less time than specified. Also, you may find you want your vegetables more charred and less tender—in that case, crank the oven to 450 and roast for less time.