Toss the brussels sprouts in the olive oil, salt and pepper, spread them out in a single layer on a baking sheet along with the cloves of garlic and roast in a preheated 400F oven until golden brown, about 20-30 minutes, flipping half way through.Squeeze the roasted garlic from the skins, mix everything, place in a baking dish and bake in a preheated 350F oven until lightly golden brown on top and bubbling on the sides, about 15-20 minutes.