Here's one of my favorite labors of love. I got this recipe from "Mexican Cooking, One Plate at a Time" on PBS. Its well worth the time and effort.
Peel all garlic cloves from the 4 bulbs (I wear latex gloves while doing this to keep the odor from lingering on my hands). Pour the oil into an 8x8" glass baking pan. Add the garlic cloves. Bake for 45 minutes in a 350 F degree oven. Remove pan from oven and use a potato masher to mash the garlic. Add the juice of the lime and return to the oven for 20 minutes more. Remove the pan and let cool. Then place the oil and garlic in a wide-mouth jar. This will last for about 2 weeks.
This is wonderful stuff. I use the oil for home fries, sauteing any kind of meats, and vegetables. You can try drizzling the oil over popcorn or salads. The garlic pieces are wonderful in spaghetti sauce, pizza, soups....let your imagination soar. I usually peel more bulbs while I'm at it and store the peeled cloves in the fridge to make more infused oil later on.