In large skillet, heat half of the oil over medium-high heat; sauté coleslaw, celery, water chestnuts, green onions, garlic, salt and pepper for 3 to 5 minutes or until softened. Sprinkle cornstarch over top; cook, stirring, for 1 minute. Stir in chicken and let cool completely.
Preheat oven to 400°F. Line baking sheet with parchment paper; set aside. Place one wrapper on clean work surface, keeping remaining wrappers covered with plastic wrap to prevent drying out. Brush edges lightly with beaten egg. Spoon about 1/4 cup chicken filling on bottom third of wrapper, leaving 1/2-inch border. Fold in sides and roll up like a burrito. Repeat to make 8 egg rolls.
Place seam side down, 3 inches apart, on prepared pan; brush rolls all over with remaining oil. Bake for 20 to 25 minutes, turn-ing halfway through cooking time, or until egg rolls are crisp and golden. Serve hot with plum sauce.
Tip: For a sweet and spicy sauce, add sriracha hot sauce to the plum sauce.