Add ⅛ cup avocado oil to a 13 x 18 baking sheet. Transfer the baking sheet to the oven.
Turn the oven to 400° F.
To a bowl, toss the Brussels sprouts with the remainder of the oil, minced garlic, and seasonings. Remove any yellow or ugly leaves from the sprouts.
Once the oven is fully heated, carefully add the seasoned Brussels sprouts, cut side down, to the baking sheet.
Roast for 10 minutes.
While the Brussels sprouts are roasting, make your balsamic glaze.
To a small pot, add the balsamic vinegar over medium heat. Bring to a boil.
Reduce the heat to low-medium and simmer for 6-10 minutes or until the vinegar has reduced and is thicker. Swirl the pot over the burner or stir while it is simmering.
The sauce will thicken as it cools.
If the sauce becomes too thick, you can reheat it and add a small drizzle of balsamic vinegar until it reaches a thinner consistency.
Flip the Brussels sprouts over and roast for an additional 10 minutes or until golden brown.
Broil on high or 500°F for 2 to 3 minutes until the Brussels sprouts are golden and toasty.
Top with parmesan cheese and a drizzle of the balsamic glaze.
You can store the leftovers in the fridge for up to 3 days.