Chinese Egg Rolls

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 scallion s (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 carrot s, cut into very thin matchsticks (1 cup)

8 large fresh shiitake mushroom s, 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

Special equipment: a deep-fat thermometer

Accompaniments: Asian sweet chile sauce ; Chinese mustard