Preheat the oven to 400°F. Set the rack in the middle position. 

Prepare the garlic heads by discarding the papery skins of the whole garlic. You should be able to see only the individual skins of the garlic cloves connected in the garlic bulb. 

Slice off the top head of the garlic, say about 1/4 inch. Place on aluminum foil and drizzle olive oil over the exposed garlic cloves. Season with salt and pepper. 

Wrap the garlic in the foil and let it bake for 40 minutes. 

Let the garlic cool slightly and then serve. 

To make it on the stovetop, you need to have individual cloves of garlic instead of the garlic bulb. Make sure you remove the paper from the garlic cloves but leave the skin on. 

Take a saucepan or a skillet. Warm 3 tbsp of olive oil and add the garlic cloves to the pan. You can roast the cloves of 2 garlic bulbs at a time. Just make sure they are not overcrowding because this will cause them to steam. 

Let them roast for about 35-40 minutes on slow to medium flame. The oil should not sizzle; this will cause the garlic cloves to fry instead of roasting. 

Remove the garlic cloves and let them cool. You can use the oil as a garlic-infused oil for pasta and salad dressings.