Cut onions into quarters, and cut each quarter in half.
Toss together sweet potatoes, onions, crushed garlic, and 2 Tbsp. olive oil; place on a lightly greased aluminum foil-lined 15- x 11-inch jelly-roll pan.
Sprinkle evenly with salt and pepper.
Bake, stirring occasionally, at 400 for 45 minutes or until tender and lightly brown.
Serve over spinach, and drizzle with Warm Bacon Dressing.