Heat a large pot over medium heat and add olive oil.
Sauté the diced onion and minced garlic until translucent, about 3-5 minutes.
Add the bell pepper and continue to cook until it softens, about 3 minutes.
Stir in the chili powder and paprika; cook for 1 minute until fragrant.
Pour in the canned tomatoes, coconut milk, and fish stock; bring to a simmer.
Add the shrimp and scallops; cook until they are done, about 3-5 minutes.
Season with salt and pepper to taste, and simmer for an additional 2-3 minutes.
Serve hot, garnished with fresh cilantro.