24 medium asparagus (1 lb)
12 (7-inch) flour tortillas (not low-fat)
1 large egg, beaten with a pinch of salt
2 tablespoons white sesame seeds
About 2 cups vegetable oil
2 tablespoons soy sauce
2 tablespoons fresh lime juice
2 tablespoons water
1 teaspoon sugar
1 scallion, finely chopped

Special equipment: wooden picks; a deep-fat thermometer

Trim asparagus to 6-inch lengths.

Halve tortillas. Brush 1 half with some of egg mixture and place 1 piece asparagus along cut side. Tightly roll up tortilla. Insert 1 pick crosswise to secure. Brush outside of roll with more of egg and sprinkle with some sesame seeds. Make 23 more rolls in same manner.

Heat 1/2 inch oil in a 10-inch heavy skillet to 350F.

Fry rolls in batches of 3, turning over once, until golden brown, about 3 minutes per batch, returning oil to 350F between batches. Transfer to paper towels to drain.

Stir together remaining ingredients until sugar is dissolved. Serve with rolls.

Cooks' note:
To take the temperature of a shallow amount of oil with a metal flat-framed deep-fat thermometer, put bulb of thermometer in skillet. Turn thermometer facedown, resting other end (not plastic handle) against rim of skillet. Check temperature frequently.