Note: Use a Dutch oven that holds 6 quarts or more. You can substitute distilled white vinegar for the sukang maasim. Look for spring roll wrappers or lumpia wrappers in the frozen foods section of an Asian market. Crisp leftover lumpia by baking them in a 425-degree oven for 8 to 10 minutes. When removed from the oven, the rolls will be soft; they will crisp as they cool. Serve warm or at room temperature. Instead of the dipping sauce, you can serve the lumpia with a store-bought sweet chili sauce or banana ketchup.

FOR THE DIPPING SAUCE: Stir all ingredients together in bowl. Let stand at room temperature for at least 30 minutes to let flavors meld or refrigerate for up to 4 days.

FOR THE LUMPIA: Process onion, carrot, celery, garlic, and ginger in food processor until finely chopped, scraping down sides of bowl as needed, about 20 seconds. Beat egg in small bowl until homogeneous. Add 2 tablespoons beaten egg to food processor, reserving remainder. Add pork, soy sauce, pepper, and salt and process until combined, scraping down sides of bowl as needed, 10 to 15 seconds. Transfer mixture to large heavy-duty zipper-lock bag and snip 1 corner to create 1-inch opening. Peel wrappers apart to separate; stack neatly and cover with very lightly dampened dish towel.

Place 1 wrapper on counter so 1 corner points to edge of counter. Pipe 5 by ¾-inch strip of filling parallel to counter, just below center of wrapper. Using pastry brush, apply light layer of egg wash onto upper 1½ inches of top corner of wrapper, making sure to brush all the way to edges. Fold bottom corner of wrapper over filling and press gently along length of filling to remove air pockets. Fold side corners over to enclose filling snugly and gently roll to form tight cylinder. Transfer, egg-washed corner down, to rimmed baking sheet or large platter. (Do not stack.) Wipe any excess egg from counter and repeat with remaining wrappers and filling, filling two at a time if you feel comfortable with it. (Lumpia can be refrigerated in single layer in airtight container for up to 24 hours. Alternatively, freeze in single layer and then stack in airtight container and freeze for up to 1 month. Do not thaw before frying.)

Heat oil in Dutch oven over medium heat to 350 degrees. Set wire rack in rimmed baking sheet. Line rack with paper towels. Using tongs, transfer 6 lumpia to oil and fry, adjusting burner, if necessary, to maintain oil temperature of 340 to 360 degrees, until lumpia are golden brown, 5 to 7 minutes (frozen lumpia will take 1 to 2 minutes longer). Transfer to prepared rack. Repeat with remaining lumpia in 2 batches. Let cool for at least 5 minutes before serving with dipping sauce.