Prepare your vegetables. Heat butter in skillet over medium-high heat until shimmering. Add onions, carrots, and cabbage. Cook 4-5 minutes, until onion is translucent. Add garlic, cooking until fragrant, about one minute. Remove from heat, then stir in corned beef.
2 carrots julienned or diced, 2 cloves garlic diced, 1 onion diced, ½ head small cabbage shredded, 1 tablespoon butter, ½ teaspoon kosher salt or to taste, ¼ teaspoon black pepper or to taste, 16-20 ounces leftover corned beef
Make Egg Rolls:
Take one egg roll wrapper and place in diamond shape. Brush edges of wrapper with water. Place 2-3 tablespoons of corned beef mixture onto the bottom of the wrapper, being sure to leave approximately 1.5 inches of space at the bottom of the wrapper.
14 egg roll wrappers, Water to brush wrappers
Fold the bottom portion of the wrapper over the mixture, then roll once. Press down both sides close to corned beef, then fold the sides in like an envelope. Roll to the top, set aside. Continue to do this until all egg rolls are prepared.
Spray egg rolls lightly with oil, then place on air fryer trays. Air Fry 14-16 minutes, until wrappers are crispy, switching trays halfway through.
Serve with spicy mustard on the side.
Notes
You can freeze egg rolls after cooking, then pull out as many as needed and reheat 5 minutes on the REheat setting.