Place the fish
in a large nonreactive mixing bowl, add the lime juice, and set aside to marinate while you proceed with the recipe.
Heat a large saute pan over medium-high heat, and add the olive oil
. Once it is hot, add the onions and cayenne peppers and saute, stirring often, until the onions are translucent, 3 to 4 minutes. Add the garlic and saute for 30 seconds. Add the diced tomatoes
, tomato paste
, stock, and 1 teaspoon of the salt, and stir well to incorporate. Bring the mixture to a boil. Season
the fish with the remaining teaspoon of salt. Then add the fish (with the lime
juice) and the coconut milk. Stir to combine, and bring the liquid to a boil. Cover the pan, reduce the heat to medium-low, and cook until the flesh of the fish starts to flake, about 10 minutes.
Remove the cover, sprinkle the cilantro
over the fish, and serve accompanied by steamed white rice