INGREDIENTS:
2 tablespoons oyster sauce
1 tablespoon soy sauce
2 teaspoons Asian sesame oil
2 teaspoons sugar
1/2 teaspoon salt
About 4 cups peanut or vegetable oil
2 teaspoons finely chopped peeled fresh ginger
2 teaspoons finely chopped garlic
1 1/2 bunches scallions (about 10), white and pale green parts cut into 2-inch lengths, then cut lengthwise into very thin matchsticks (2 1/2 cups)
2 celery ribs, cut into very thin matchsticks (2 cups)
2 medium carrots, cut into very thin matchsticks (1 cup)
8 large fresh shiitake mushrooms, stems discarded and caps sliced 1/4 inch thick (3 cups)
1 lb medium shrimp in shell (31 to 35 per lb), peeled, deveined, and coarsely chopped
1/4 lb Chinese roast pork (char siu) or leftover roast pork, cut into 2-inch lengths, then cut lengthwise into very thin matchsticks
1 (1-lb) package Asian egg roll or spring roll wrappers
1 large egg, lightly beaten
DIRECTIONS:
Make filling:
Stir together oyster sauce, soy sauce, sesame oil, sugar, and salt in a small bowl until sugar and salt are dissolved.
Heat a dry 12-inch heavy skillet (not nonstick) over moderately high heat until hot but not smoking, then add 2 tablespoons peanut oil, swirling skillet to coat. Stir-fry ginger, garlic, and scallions until scallions are wilted, about 1 minute. Add celery, carrots, and mushrooms and stir-fry until vegetables are softened, 4 to 6 minutes. Push vegetables toward edge of skillet, then add shrimp to center and stir-fry until shrimp are just cooked through, 3 to 5 minutes. Add pork and oyster sauce mixture and stir together all ingredients in skillet until combined. Season with salt and transfer to a large shallow bowl. Cool, stirring occasionally, about 30 minutes.
Make egg rolls:
Gently peel apart wrappers to separate if necessary (wrappers may not be perfectly square).
Put 1 wrapper on a work surface, arranging wrapper with a corner nearest you and keeping remaining wrappers covered with plastic wrap. Stir filling, then spread a scant 1/4 cup filling horizontally across center of wrapper to form a 4-inch log. Fold bottom corner over filling, then fold in side corners. Brush top corner with egg and roll up wrapper tightly to enclose filling, sealing roll closed with top corner. Transfer roll, seam side down, to a paper-towel-lined baking sheet and loosely cover with plastic wrap. Make more egg rolls in same manner, transferring to baking sheet as formed (you may have some filling left over).
Put oven rack in middle position and preheat oven to 250°F. Line a large colander with paper towels. Heat 1 inch peanut oil in a 5- to 6-quart wide heavy pot until it registers 350°F on thermometer, then fry 4 or 5 egg rolls (don’t crowd pot), turning with a slotted spoon, until golden brown, 3 to 5 minutes. Transfer with slotted spoon to colander and drain rolls upright 2 to 3 minutes, then keep warm on a rack set on a large baking sheet in oven. Fry remaining egg rolls in batches, transferring to colander and then to rack in oven.
