In a food processor, combine chickpeas, sweet peppers and lemon juice. Cover and process until mixture forms a fine paste. Add parsley leaves, tahini, the 2 tablespoons oil, soy sauce (if using), garlic, black pepper and cayenne pepper. Cover and process until smooth. Spoon into a serving bowl. Serve immediately or cover and chill up to 24 hours. Just before serving, drizzle with additional olive oil. Serve with pita wedges or crisps, bagel chips, and/or carrots and celery. Makes 6 appetizer servings (1-1/2 cups)