Right on the tray, toss the Brussels sprouts with olive oil, water, garlic, and salt. Make sure all of the Brussels sprouts are lying sliced side down if they are cut in half. Sprinkle the bacon over the top and cover the baking sheet with aluminum foil, making sure to seal it around the edges.
2 pounds Brussels sprouts, 3 tablespoons olive oil, 1 tablespoon water, 3 cloves garlic, 6 slices bacon