Preheat a large pot over medium-high heat.

Season both sides of the marrow bones and flanken with one tablespoon salt and one tablespoon pepper. Add oil to the pot, then place both marrow bones and one piece of flanken. Sear for three to four minutes on each side until browned, then remove from the pot and set aside. Place all the seared flanken into a mesh soup bag so that it can be easily removed later.

Place remaining pieces of flanken in the pot and brown for three to four minutes on each side, then remove and set aside.

At this point, the bones and meat may have rendered their own fat. If so, remove all but two tablespoons of fat.

Add onion, carrots, and celery to the pot. Sprinkle in remaining salt and pepper. Cook, stirring often, for 10-12 minutes, until the veggies are very soft and just begin to very lightly brown. Pour in vinegar and lemon juice. Using a wooden spoon, scrape up any bits that got stuck to the bottom of the pan (these are flavor bombs!). Return all the meat and bones to the pot. Fill with water and add herbs.

Bring soup to a boil. (You can use a fine mesh strainer to remove any debris that floats to the top.) Once boiling, reduce heat to low, cover the pot, and simmer for five to six hours. At this point, remove the mesh bag containing the flanken and allow to cool for 30 minutes.

Wearing gloves, or using two forks, shred the meat off the bones. Discard bones and fat.

Lay out wonton wrappers on a clean surface. Prepare a small bowl of water. Place one tablespoon of shredded meat in the center of each square. Brush the edges of the square with a small amount of water. Fold in half on the diagonal, then take the two ends of the triangle and pinch together. Drop into boiling soup and cook until done, three to five minutes.

The wontons will slightly thicken the soup (due to the small amount of cornstarch on the wrapper), and make it even more filling and delicious. Serve hot and enjoy!