1. Preheat oven to 400ºF. Cut off top of garlic head, place on a piece of foil, drizzle with oil and sprinkle with salt and pepper. Wrap tightly and roast until tender, 30 to 40 minutes. Let cool.
2. Over an open flame or under a preheated broiler, cook bell pepper, turning frequently with tongs, until blackened all over. Place in a paper bag, close tightly and allow pepper to sweat for 10 minutes. Slip off pepper skin with your fingers.
3. Roughly chop pepper, discarding seeds and membranes. Squeeze garlic cloves out of skins. Place pepper and garlic in food processor; add cumin, coriander and sour cream; puree until smooth. Season with salt and cayenne pepper. Cover and chill. Serve with assorted crudités and crackers.
Note: Nutritional analysis is for dip only.