Preheat the oven to 450˚F. Lightly grease a rimmed baking sheet with cooking spray and set aside.

In a large mixing bowl, combine the trimmed Brussels sprouts, 3 tablespoons of olive oil, 1 clove of minced garlic, ½ teaspoon salt, and ¼ teaspoon pepper. Mix until well combined. Transfer Brussels sprouts to the prepared baking sheet, spread them in a single layer, and bake for 14 minutes, stirring once or twice during cooking.

Prepare the salmon by drizzling with 1 tablespoon of olive oil and evenly dividing and pressing 4 cloves of minced garlic on top of each fillet. Season the salmon with 1 tablespoon of oregano, ¾ teaspoon salt, and ¼ teaspoon pepper.

Remove the baking sheet from the oven and move the Brussels sprouts around to create space for the salmon fillets. Place the salmon on the baking sheet and bake for an additional 10 to 12 minutes, or until cooked through. Larger fillets may need a couple more minutes.

Remove from the oven. Let the salmon and veggies stand for a few minutes before serving.