Creamy Pancetta Dressing and Iceberg Lettuce

I adopted this recipe from Recipezaar and have since made the recipe. It's very good and the only change I made was using 1 teaspoon dried thyme, as I didn't have fresh in the garden. The original poster said this recipe was adapted from Michael Chiarello.

• Ready In: 45 mins
• Serves: 12

Ingredients

• 3  tablespoons olive oil
• 1 1⁄2 cups  roughly cut pancetta
• 1  onion, finely chopped
• 1  garlic clove, minced
• 2  tablespoons  minced fresh thyme leaves
• 1⁄4 cup cider vinegar
• 1  cup mayonnaise
• 1  cup sour cream
•  fresh ground black pepper
• 3  heads iceberg lettuce, quartered and cleaned

Directions

1. Heat a saucepan over medium-high heat.
2. When the pan is hot, add the olive and heat.
3. When the oil is hot, add pancetta and saute, and caramelize for about 10 to 15 minutes.
4. Stir onion into mixture, toss and saute for another 10 minutes, until the onion begins to brown.
5. Add garlic, thyme, and cider vinegar, and remove from heat.
6. Allow mixture to cool for about a 1/2 an hour.
7. Place cooled mixture into bowl, add mayonnaise and sour cream.
8. Season with black pepper, to taste.
9. Serve over iceberg wedges.