Wonton Soup with Bok Choy

Ingredients

• 1.5 lb bok choy halved lengthwise thinly sliced
• 2 lb chicken thighs 
• 1 large egg yolk 
• 1.5 inch ginger fresh peeled finely chopped
• 2 inch ginger fresh peeled chopped
• 0.5 lb ground pork lean (not )
• 2 lb pork ribs country-style (meaty)
• 1 teaspoon rice vinegar (not seasoned)
• 0.5 teaspoon salt 
• 2  scallions finely chopped
• 0.5 teaspoon asian sesame oil 
• 1 tablespoon soya sauce 
• 12 cups water 
• 0.3 teaspoon pepper white
• 30  wonton wrappers frozen thawed

Equipment

• bowl
• baking sheet
• pot
• sieve
• plastic wrap
• ziploc bags

Directions

1. Simmer pork ribs, chicken, scallions, ginger, and water in a 6- to 8-quart tall narrow stockpot, uncovered, until meat is very tender and falling apart, 4 1/2 to 5 hours.
2. Pour broth through a sieve into a large bowl and discard solids. Cool broth, uncovered, then chill, covered, at least 1 1/2 hours.
3. Stir together pork, yolk, scallions, ginger, soy sauce, vinegar, sesame oil, salt, and white pepper in a bowl in 1 direction with your hand until just combined (do not overwork, or filling will be tough).
4. Put 1 wonton wrapper on a work surface (keep remaining wrappers covered with plastic wrap). Spoon a rounded teaspoon of filling in center of square, then brush water around edges. Lift 2 opposite corners together to form a triangle and enclose filling, pressing edges firmly around mound of filling to eliminate air pockets and seal. Moisten opposite corners of long side. Curl moistened corners toward each other, overlapping one on top of the other, and carefully press corners together to seal. Make more wontons in same manner.
5. Skim any fat from broth, then bring to a simmer in a 5- to 6-quart pot. Stir in bok choy, salt, and white pepper and simmer, uncovered, until bok choy is crisp-tender, 3 to 4 minutes.
6. Add wontons and simmer, uncovered, gently stirring, until filling is just cooked through, about 3 minutes (cut 1 open to check).
7. ·Broth can be chilled up to 1 day. ·Wontons can be made 1 month ahead. Freeze in 1 layer on a plastic-wrap-lined baking sheet until firm, about 30 minutes, then transfer to a sealable plastic bag and keep frozen.