Pour this rich dressing over wedges of crisp iceberg lettuce or quartered heads of romaine for a wonderful salad.
- Preheat oven to 400°F
- Cut top 1/2 inch off heads of garlic, exposing cloves.
- Place each on square of foil.
- Drizzle with oil, then enclose in foil.
- Place on oven rack; bake until garlic is tender, about 45 minutes.
- Open foil; cool garlic slightly.
- Hold 1 head of garlic, cut side down, over medium bowl and squeeze, releasing roasted garlic pulp into bowl.
- Repeat with remaining garlic.
- Mash until smooth.
- Whisk in mayonnaise, buttermilk, Parmesan cheese, lemon juice, and Worcestershire sauce.
- Season to taste with salt and pepper.
- Cover and chill until ready to use, up to 2 days.