SPREAD all the broccoli on a rimmed baking sheet and broil—with no oil—until it is slightly softened and nicely charred on most surfaces, turning once, 5 to 7 minutes. You can also do this on a grill, but you’ll need a grill basket.
PILE the broccoli into a bowl and squeeze the half lemon all over it.
SEASON with ½ teaspoon chile flakes and generous amounts of salt and black pepper.
ADD ¼ cup olive oil and toss.
TASTE and adjust the seasoning until it’s delicious.
ARRANGE the broccoli on a serving platter, grate a nice shower of pecorino over the top, sprinkle on the breadcrumbs, if using, and serve with the lemon wedges. Set out the tonnato as a dip.