Pat the fish fillets dry with paper towels. Cut into bite-sized strips or pieces.
In a medium bowl, whisk together garlic powder, salt, pepper, and mustard.
Add the water or beer and whisk thoroughly.
Then add the flour and baking powder and mix until combined.
Heat about 1 inch of coconut oil in a large skillet over medium-high heat until it reaches 375 degrees or simmering.
Dip each piece of fish into the mixture, allowing excess to drip off.
Fry the fish pieces in batches, being careful not to overcrowd the pan.
Cook for about 2-3 minutes per side, or until golden brown and cooked through.
Transfer to a paper towel-lined plate to drain excess oil.