Heat butter in a large, non-stick soup pot over medium heat. Add onions, red pepper, celery, and garlic. Cook and stir until vegetables begin to soften, about 4 minutes.
Stir in sweet potatoes, ginger root, cumin, coriander, curry powder, and cinnamon. Cook and stir for 30 seconds. Add broth, coconut milk, salt, and pepper. Bring soup to a boil. Reduce heat to low, cover, and simmer for 10 minutes, just until sweet potatoes are tender.
Transfer half the soup to a blender and purée until smooth. Return puréed soup to pot with remaining soup. Stir in cilantro, basil, peanut butter, brown sugar, and lime juice. Mix well. Add shrimp and heat for about 2 more minutes, just until shrimp is hot.
Recipe from: Podleski, Janet and Greta. Eat, Shrink & Be Merry. "Thai One On." Granet Publishing, 2005, pp. 52.