Cut off the top 1/4-inch of each head of garlic: try to have a cut edge on each clove so you can pop them out after roasting. Peel away the paper on the outside of the head (the bottom stem will keep the cloves together). Place the garlic heads on a sheet of aluminum foil. Drizzle them with olive oil and season them with salt and pepper. Close up and seal the packet.
Roast the garlic about 45 minutes to 1 hour, until a clove in the center is golden in color and soft when pierced with a sharp knife (and your kitchen smells incredible!). Cool until able to handle, or store refrigerated for up to 2 weeks. To remove the garlic, squeeze the bottom of the clove so it pops out the top. Spread on crusty bread, use in sauces and salad dressings, or in mashed potatoes.