Red Pepper and Hazelnut Sauce (Romesco)

Romesco sauce is a fabulous accompaniment to nearly anything off the grill - meat, fish, poultry, or vegetables. The sauce is also great on pasta or slathered in a sandwich. It makes a great dip too.

1 1/2 cups (12 oz.) roasted red peppers (jarred or frozen work well)
1/4 cup hazelnuts, roasted and skinned
2 cloves garlic, peeled
2 tablespoons sherry vinegar
1 tablespoon coarsely chopped fresh rosemary
1 tablespoon fresh marjoram or Italian oregano
1 teaspoon sugar
1 teaspoon salt
1/2 teaspoon red pepper flakes or hot paprika to taste
1/2 cup extra virgin olive oil, use part hazelnut oil for extra nutty flavor

Process all the ingredients except the oil in a food processor or blender until the hazelnuts are finely ground. Stop the machine and scrape down the sides. With the machine running, pour in the olive oil in a steady stream. The sauce should have the consistency of thick salad dressing. Taste and add more salt if desired. The sauce stores well in the refrigerator but will thicken when cold. Bring it to room temperature before serving or warm the sauce gently by stirring it in a stainless-steel bowl set over simmering water. Don't overheat the sauce or the oil will separate.

Makes about 2 1/4 cups.