In a Dutch oven, heat butter over medium-high heat. Add onion; cook and stir until tender, 4-5 minutes. Add broth, potatoes, corn, coconut milk, bamboo shoots, curry powder, chili paste if desired, salt and pepper. Bring to a boil; reduce heat. Simmer, uncovered, until flavors have blended, 12-15 minutes, stirring occasionally., Add shrimp; heat through. Prepare rice according to package directions; serve with curry. Sprinkle with additional curry powder. If desired, serve with lime wedges and basil.