Preheat oven to 350 degrees F.
Slice off top of the garlic bulbs, wrap in foil and roast for 1 hour. Set aside and allow bulbs to cool. Squeeze the roasted garlic from the bulbs into a food processor, and add the oil, lemon juice and rosemary. Process until mixture is smooth.
Raise the oven temperature to 400 degrees F.
Place fillets on well-oiled, foil-covered baking sheet. Salt and pepper the fillets liberally. Spread puree over the fillets, making sure all the flesh is well covered. Let fish marinate in refrigerator for 30 minutes.
Bake fish for 12 to 15 minutes, until the meat flakes easily and has a somewhat darker appearance on the inside.
Broil for another 2 minutes to brown the tops of the fillets.
Recipe courtesy of Jordy Rosenhek, Wild Edibles, NYC