Roast the whole bulb of garlic in a roasting pan in the oven. Separate the garlic cloves, peel, and mash in a small bowl to form a paste. Set aside.
Peel the onions and cut off the ends. Place the onions in a pot of boiling water and simmer for 20 minutes. Drain and allow to cool for 15 minutes. Then cut the onions in half across the middle and remove the cores, leaving the outer three