1 cup red onion, 2 cups Brussels sprouts, 1 cup carrots, 1 cup broccoli, 1 cup cauliflower
Add the olive oil, sumac, and salt and pepper, and toss well to combine using your hands or kitchen tongs.
2 Tablespoons extra virgin olive oil, 1 teaspoon sumac, salt and pepper
Spread the vegetables out in a single layer on a large rimmed sheet pan lined with parchment paper for easier cleanup.
Roast the vegetables for 25 to 30 minutes until tender when pierced with a fork and lightly browned, stirring half way through. Serve immediately.
Notes
Tips for cutting the vegetables:
Broccoli, cauliflower, and Brussels sprouts cook at about the same rate when cut the same size.
Carrots take a little longer, so cut them in quarter-inch coins.
Onions take even longer to roast than carrots, so cut them in thin slices.
Roasting tips:
If you are cooking something else in the oven, you can roast the vegetables at the same time, as long as the oven temperature is between 400° and 450°F. The higher the temperature, the quicker they will take to cook, so keep your eye on them so they don't burn.
Spread the vegetables out in a single layer and do not overcrowd the pan to ensure they roast instead of steam.
Storing: Leftovers can be covered and refrigerated for up to 4 days. They can be reheated in the oven or microwave. Roasted vegetables are also delicious served cold in a salad.