Add the ground pork, onion, and carrots. Cook until the pork is no longer pink.
Pour in the remaining 1/2 tablespoon oil and add the cabbage, and if using, sprouts; cook 3 more minutes.
Add the hoisin sauce,tamari sauce, sugar, and salt; stir.
If battering and frying the egg rolls the same day, allow the mixture to reach room temperature. Then, toss the mixture with the egg white. Then, evenly distribute the mixture onto a baking sheet, cover, and refrigerate overnight or at least 2 hours. (If you’re making the egg rolls in the following days up to 3], don’t combine the raw egg white with the mixture until just prior to filling. However, do spread the mixture out in the baking sheet as it gives it a chance to dry out.)
Preheat a deep-fryer or pan filled with at least 3 inches of oil to 375°F. (A deep-fryer works best, as it is difficult to keep the temperature even over the stove. However, it can be done. Just note that when you add the egg rolls to the oil the temperature drops significantly, especially if the egg rolls just came out of the refrigerator.)
You can freeze any fried egg rolls once they reach room temperature. To rewarm, bake in a preheated 350°F oven or 300°F toaster oven for 20 minutes or until thoroughly heated.
*If you wish to use tonic water, omit one of the tablespoons of sugar.