In a blender, place 2 garlic cloves, ¼ cup onion, 1 cup sour cream, chicken broth, and chipotle chiles. Blend on High until the mixture has a light and smooth consistency. Heat the olive oil in a 12-inch skillet over medium-high heat. Add ½ cup onions and cook, stirring constantly, for 1 minute. Add 3 cloves garlic and cook for another minute or until the onions are translucent. Stir in the shrimp and cook for 4 to 6 minutes or until shrimp are pink and firm. Turn the heat to medium. Add the creamy sauce and mix, stirring constantly, until the sauce starts to bubble and is heated through. Serve on a platter over rice.