Prepare the Filling:
Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat.
Add the ground meat (if using) and cook until browned, breaking it into small pieces.
Stir in the garlic, ginger, cabbage, carrots, and green onions. Cook for 3–5 minutes, until the vegetables soften.
Add the soy sauce, sesame oil, and black pepper. Mix well and cook for an additional 1–2 minutes.
Remove from heat and let the filling cool slightly.
Assemble the Egg Rolls:
Lay an egg roll wrapper on a flat surface, with one corner pointing toward you (diamond shape).
Place 2–3 tablespoons of the filling in the center of the wrapper.
Fold the bottom corner over the filling, then fold in the sides to create an envelope shape.
Roll the wrapper tightly toward the top corner. Brush the top corner with beaten egg to seal the roll.
Repeat with the remaining wrappers and filling. Cover the assembled egg rolls with a damp towel to prevent drying out.
Fry the Egg Rolls:
Heat vegetable oil in a deep frying pan or pot to 350°F (175°C).
Fry the egg rolls in small batches for 3–4 minutes, turning occasionally, until golden brown and crispy.
Use tongs to transfer the egg rolls to a plate lined with paper towels to drain excess oil.
Serve:
Serve the egg rolls hot with sweet and sour sauce, soy sauce, or your favorite dipping sauce.