Preheat oven to 400 degrees F.
Place brussels sprouts and onion into a bowl.
Pour 1 TBSP of olive oil over the vegetables and sprinkle in the salt, pepper, and garlic powder.
Toss together to coat the vegetables evenly with the oil and spices.
Place veggies onto an oiled sheet pan in an even layer.
Roast in oven for about 20 minutes, or until desired tenderness and color.
In a small bowl, mix together 1 TBSP of olive oil with honey and balsamic vinegar.
Once brussels sprouts and onions are done, transfer them to a bowl and pour the honey/balsamic mixture over them. Give them a gentle toss to coat and then serve. Enjoy!