Heat a sauce pot with the butter over medium high heat. Add the onions and sauté for 1 minute. Add the garlic and ginger and sauté another 3 minutes. Add the coconut milk, fish sauce, 1 teaspoon salt and stevia. Simmer for 15-30 minutes. Add the cream cheese and use a stick blender to purée until smooth. Taste and add sweetness to your liking.

The sauce can be made 3 days ahead of time and kept in the fridge in an airtight container until ready to use. To reheat, place in a sauce pot over medium heat for 3 minutes or until heated through.

While the sauce is simmering, make the fish.

Heat a cast iron skillet to medium high heat. Add the butter. Pat the fish fillets dry and season well on all sides with salt. Place into the hot skillet and cook for 3 to 4 minutes, flip and cook another 4 minutes or until fish is cooked though and no longer opaque inside (timing will depend on thickness of the filet).

Remove fish from the skillet and place on a serving platter. Cover each filet with a few tablespoons of sauce and enjoy!