Preheat oven to 425 degrees. Place sheet pan in oven while preheating.
Cut broccoli into florets, leaving some stem intact. Combine broccoli, garlic and oil in large bowl. Season generously with salt and pepper.
Place broccoli on preheated sheet pan and roast in the oven for 15-20 minutes, shaking and/or turning broccoli halfway through. The broccoli will have brown, crispy tips when done.
If using olive oil instead of canola or grapeseed oil, lower the oven temperature to 400°F. Olive oil has a lower smoke point than canola and grapeseed oils and may take on a slightly bitter flavor if used at too high of a temperature for an extended period of time.