Slice bell peppers in half, lengthwise and scoop out seeds and membranes. Lay peppers, flesh side down on a foil-covered baking sheet. Lightly smash peppers with the palm of your hand. Broil 15 minutes or until skin is black. Place in a resealable plastic bag, seal and let rest 15 minutes. Take skin off peppers. Using a food processor or blender, puree red peppers, sour cream, oil, lemon juice, salt, pepper, and garlic until smooth. Refrigerate mixture until ready to serve.
Boil a pot of water and cook shrimp 3 minutes or until fully cooked. Take skin off of shrimp. Wrap with plastic wrap and refrigerate until chilled. Serve sauce as a dipping sauce.