Mix everything in a bowl and mash together. Dump onto a cookie sheet covered in parchment. Flatten slightly. Freeze for 30 minutes.
Cover with waxed paper and roll out to desired thickness. Freeze until solid, about 45 minutes.
Using a pizza cutter, cut into rectangles (about 2 ½ by 4 inches). Place rectangles into the freezer (on fresh parchment) until ready to use.
Using a pan with at least 3 inch sides, heat oil to 350 degrees (I just use the medium setting on my stovetop). Oil only needs to be about ¾ inch deep.
Cook batches in the oil for about 2 minutes, 30 seconds until light brown. Turn them over half way through. Remove from oil and drain on a rack. After a couple of batches are done, place already fried hash browns back into the hot oil for 30 seconds. This 2nd dunk makes them extra crispy. Remove from oil and drain on rack.
Once they are completely cool, place on a cookie sheet and freeze. Store in a plastic freezer bag. They can be removed from the freezer and placed straight in the toaster, medium high setting.