Add all ingredients for meatballs together in a food processor. Set aside in refrigerator for 30 minutes.
In a large Dutch oven add the oil. Saute the onions for 10 minutes. Add the poblano chilies and cook 2 minutes. Add the garlic and cook 1 minute. Add the tomatoes, fish stock, tomato paste, brown sugar and bay leaves.
Bring to a boil. Let simmer 30 minutes over low heat. Shape the shrimp meatballs into 12 meatballs. Drop them carefully in the liquid and poach them for 5 minutes. Remove and discard bay leaves. Serve garnished with cilantro