Pre-heat the oven to 450
Mince 2 garlic cloves and mix in a small bowl with oregano, oil, salt and pepper. Toss the remaining halved garlic, Brussels sprouts and oil mixture in a large roasting pan. Roast for 15 minutes, stirring once.
Add wine to the remaining oil mixture. Remove the pan from the oven, stir the vegetables and place the salmon on top. Drizzle with the wine mixture. Sprinkle with the remaining 1 tablespoon oregano, & 1/2 each of salt & pepper. Bake until salmon is cooked through, 5 or 10 minutes more.