Combine the dark roux and the 3 cups of water. Cook on high heat until roux is dissolved and it comes to a rolling boil — be sure to continue to stir so it doesn’t stick.
Add onions, bell peppers and garlic. Cook until vegetables are clear.
Simmer for 20 minutes.
Add in shrimp, green onions, parsley and seasoning to taste. Cook on high for 5 minutes.
If too thick, add ½ - 1 cup of water for the right consistency.