Heat a cast-iron skillet over medium heat for about 5 minutes. Then add enough olive or avocado oil to cover the bottom of the skillet. Place the egg roll "seam side" down in the oil.
Cook it until that side is crispy and brown, and then flip. When finished cooking, place them on a plate lined with newspaper or paper towels to absorb the extra oil.
Baking Instructions
Place a baking rack on a foil-lined baking sheet. Liberally spray the rack with olive oil.
Put the egg rolls seam side down on the baking rack and brush olive oil over the top.
Bake at 325 F for 12 minutes, and flip. Bake for an additional 8-12 minutes or until the egg rolls are nice and crispy without being burned.
Notes
To freeze: place uncooked egg rolls on a baking sheet lined with parchment paper, and freeze. Then transfer to a freezer-proof bag or container. Do not thaw before cooking.