Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large skillet, heat the olive oil over medium heat. Add the cabbage, carrots, and mushrooms, sautéing until the vegetables are tender, about 5-7 minutes.
Stir in the green onions, parsley, chives, soy sauce, salt, and pepper, cooking for an additional 2 minutes. Remove from heat and let the mixture cool slightly.
Place an egg roll wrapper on a clean surface, with one corner pointing towards you. Spoon about 2 tablespoons of the vegetable mixture onto the center of the wrapper.
Fold the bottom corner over the filling, then fold in the sides. Brush the top corner with the beaten egg and roll up tightly to seal.
Place the rolls seam side down on the prepared baking sheet. Brush the tops with the remaining beaten egg.
Bake in the preheated oven for 15-20 minutes, or until the rolls are golden brown and crispy.
Allow to cool slightly before serving.

Variations & Tips
For a spicier kick, add a teaspoon of grated ginger or a pinch of red pepper flakes to the vegetable mixture. You can also experiment with different herbs, such as cilantro or basil, for a unique flavor profile. If you prefer a non-vegetarian version, add some cooked, shredded chicken or shrimp to the filling. For a gluten-free option, use rice paper wrappers instead of traditional egg roll wrappers, and bake as directed.