To reheat any leftover egg rolls, add the cold fried egg rolls in a single layer to an air fryer basket, spacing them apart. Lightly spray the tops with canola oil spray and cook at 350 degrees F, flipping halfway through, until crispy, about 10 minutes. You can buy char siu from Chinese barbecue restaurants and some Asian markets. Alternatively, substitute ground meats, such as pork, chicken or turkey; brown it first in the vegetable oil before adding the garlic and ginger. You can freeze the ungreased and uncooked egg rolls in a single layer, spaced apart, on a plate or baking sheet. Transfer to an airtight container and freeze for up to 2 months. Cook from frozen, following the reheating directions.