Whenever I roast sliced garlic I seem to burn it. Advice ?

i also find it's helpful in this recipe to take the sheet pan out about halfway through, give everything a bit of a stir, and rotate the sheet when i place it back in the oven. i dont think you lose the nice char on the broccoli and it helps prevent burning either the garlic or the broccoli.

I hear you—you could also try slicing it a little thicker than you normally would (and making sure your broccoli pieces aren't so thick they'll take a long time to roast), and also making sure there aren't any garlic slices exposed way out on their own on the baking sheet—they'll be the first to burn.

If it is getting done too quickly, add it halfway between roasting.