1. Begin by heating a large skillet or wok over medium-high heat. Add the ground pork and cook until no longer pink, breaking it apart with a spoon as it cooks.
2. To the browned pork, add the shredded cabbage, carrots, scallions, garlic, and ginger. Stir-fry the mixture for about 3-4 minutes until the vegetables soften.
3. Pour in the soy sauce, oyster sauce, sesame oil, and white pepper. Stir to combine everything evenly and cook for another 2 minutes. Then, remove the filling from heat and allow it to cool slightly.
4. In a small bowl, mix the cornstarch with water to create a slurry. This will be used to seal the egg roll wrappers.
5. Lay out one egg roll wrapper with a corner pointing towards you. Place about 2-3 tablespoons of the filling in the center of the wrapper. Fold the corner closest to you over the filling, tuck in the sides, and roll tightly. Seal the final corner with a dab of the cornstarch slurry.
6. Heat oil in a deep fryer or a large, heavy-bottomed pan to 350°F (175°C). Fry the egg rolls in batches, without overcrowding, until golden brown and crispy, about 2-3 minutes per side. Drain on paper towels.