In a Dutch oven, saute onions in butter until tender. Add garlic; cook 1 minute longer. Add the potatoes, red peppers and broth. Bring to a boil. Reduce heat; cover and simmer for 15-20 minutes or until vegetables are tender. Remove from the heat. Add pears with juice; let cool., Using a blender, puree soup in batches. Return to the pan. Stir in cayenne and black pepper. Cook until heated through. If desired, serve with chopped chives, heavy cream and croutons.