On the bottom side of the shrimp, make two cuts near the top to straighten it out. This will keep the shrimp from curling too much when it is cooked.
Turn the shrimp over and make an incision from the head to the tail, about 3/4 of the way through. This is also where you will devein the shrimp- remove the poopy stuff if any.
Use your knife and hands to flatten the shrimp, then season with your seasoning salt. Store in the refrigerator for now.
Get three bowls: in the first one, put about 1/4 cup of AP flour. In the second one, mix together the panko and shredded coconut (dry batter).Note: if you want a cleaner presentation, pulse the shredded coconut a few times in a blender first.
In the third bowl, mix together 1/3 cup AP flour, 1/4 cup corn starch, 1/2 tsp baking soda, 1 tsp salt, and about 1/2 cup of cold club soda (wet batter). You may need more or less club soda- look for the consistency shown in the picture below. It should be a little thinner than pancake batter.
First coat the shrimp in AP flour to make the wet batter stick. Then dip in the wet batter and shake off the excess. Then dip into the dry batter and press firmly until it is nicely coated. Note: I recommend coating ALL the shrimp first, at one time. If you try to do it as you go while frying, you will most likely burn the shrimp because you can't work fast enough.
Pour enough oil into a pan to shallow fry the shrimp. Bring it to about 300 degrees Fahrenheit. You don't want the oil to be too hot or the coconut will burn.
Fry in batches for about 2 minutes on each side or until golden brown.
Remove from oil and dry on a wire rack.
Remove all the leftover fried bits at the bottom of the pan, then continue frying the remaining shrimps.
Serve as an appetizer with sweet chili sauce or as a meal with some rice, cabbage, and kimchi.