Start by preheating your oven to 400 degrees and washing the produce.
Trim off the brown ends of the Brussels sprouts and slice the heads into quarters. Set them aside.
Peel the carrots and then follow the same process: slice off any brown ends and cut the carrots into thin, round slices.
Add the veggies to a bowl and top them with olive oil, salt, pepper, and garlic powder. Use a spoon to toss the Brussels sprouts and carrots in the seasonings.
Lay out seasoned veggies on a parchment paper-lined baking sheet. Arrange into a single layer for the best roasting.
Pop baking sheet into the oven and cook veggies for about 30 minutes. Cooking time will ultimately depend on your oven and the size of the veggie slices.
Once they are done, remove the Brussels sprouts and carrots from the oven. They are ready to be enjoyed.