Make seasoning: Put the ginger paste, coarse sea salt, bell pepper, pepper, cilantro, and garlic in a mortar and pestle, crush until you obtain a coarse paste (see picture).
Toast coconut: Heat the oil in a heavy saucepan over medium fire.Add the ground coconut, stir constantly until it gets to a light golden color. Be careful that it doesn't burn.
Cook seasoning: Add the seasoning, and cook and stir until the seasonings start to release their fragrance (1 to 2 minutes).Add the bija (anato) powder and mix it well.
Simmer: Add the coconut milk, stir and cook over low heat for about 5 minutes (stir once or twice to prevent it from sticking to the bottom and burning)
Make thickener: Dissolve the cornstarch and lime juice in the water. Add to the boiling sauce and stir until it is mixed completely.
Cook shrimp: Stir in the shrimp. Cover with a lid and simmer over medium-low heat for about 3 minutes, turn the shrimp, and simmer another 3 minutes, or until they turn a bright pink color. Season with salt to taste. Remove from the heat.
To make the ginger paste peel and wash a large ginger root, and blend in a food processor. If you don't have a food processor grate it with the fine side of the grater.Keto option: Even adding cornstarch this dish is quite low in carbohydrates, so it's an excellent keto option, but the cornstarch doesn't add any flavor, so you can leave it out. If you still want a thicker sauce, just add more coconut oil, or your favorite keto thickener (a dash of xanthan gum works well). The suggestions for accompanying it are not appropriate for the keto diet, so you'll have to find alternatives.