Melt 1 tablespoon of coconut oil in saute pan and then add the mustard seeds. Once the mustard seeds begin to pop, add the onion and serrano pepper.

Cook for 8-10 minutes, or until the onions begin to brown. Then add the garlic and ginger, stir for 30 seconds, then turn off the heat.

Scoop everything from out of the pan and put it into a food processor or blender along with the water. Puree until smooth.

Pour this back into the pan over medium heat. Add the spices and mix well. Then add the fish and mix well.

Add the remaining coconut oil to the pan, cover with a lid and cook for 6-8 minutes, or until the fish is cooked through.

Put the tamarind paste into a small bowl and then pour some of the hot liquid from the fish curry into the bowl to completely dissolve the paste. Add this back to the pan.

Stir in the coconut milk, garnish with cilantro and serve.

Note: this fish curry tastes better the next day.