In a blender combine onion, garlic, lemongrass, ginger, lime zest, lime juice, kaffir leaf, paprika, turmeric, coconut oil, fish sauce, brown sugar, pepper, chili flakes, cumin, and coriander. Blend until smooth.
Heat a large pot that has a lid over medium heat. Now add the curry paste and cook until fragrant. Add the mussels, turn to high heat and put the lid on top. Cook for 2 minutes and then add the coconut milk. Continue to cook until mussels open completely.
Remove lid, tear and add basil. Adjust seasoning and serve with steamed rice.