Slow Cooker Pork Ramen

1. 1
   Season the pork with salt.
2. 2
   This step and the next are optional: Put a flameproof slow cooker insert on the stovetop over medium-high heat, then add the oil and warm until hot. (Or, use a frying pan for this step). Working in batches if necessary to avoid crowding, add the pork pieces and sear them on the first side without moving them until well browned, 3 to 4 minutes. Turn the pieces and sear on the second side until well browned, 3 to 4 minutes longer. Transfer to a plate and set aside.
3. 3
   Pour off all but 2 tablespoons of the fat from the insert and return the insert to medium-high heat. Add the yellow onion and sear, without stirring, until browned, about 5 minutes. Stir in the garlic, ginger, and 1 cup of the broth and deglaze the insert, stirring and scraping up any browned bits from the insert bottom, then let simmer for 1 minute.
4. 4
   If you have included the browning step, transfer the insert to the slow cooker, add the leek, mushrooms, and the remaining 7 cups of broth, and stir to combine. If you are starting here, combine the pork, yellow onion, garlic, ginger, leek, mushrooms, and broth in the slow cooker. Cover and cook on the low-heat setting for 8 hours. The pork should be very tender and the broth should be fragrant.

To assemble:

1. 1
   Transfer the pork to a cutting board. Using 2 forks, break the pork into bite-size chunks, removing and discarding any large pieces of fat. Strain the broth through a fine-mesh sieve into a bowl and discard the solids. Using a large spoon, skim off and discard any fat from the surface of the broth. Return the pork and broth to the slow cooker and season to taste with soy sauce and sesame and/or chile oil. Cover and cook on the low-heat setting for about 30 minutes to warm through.
2. 2
   Cook the ramen noodles according to the package directions. If you want to top each bowl of ramen with an egg, put the eggs into boiling water and simmer for 5 to 6 minutes. Remove the eggs from the water, let cool until they can be handled, and peel them.

To serve:

1. 1
   Divide the noodles evenly among individual bowls. Ladle the broth and pork over the noodles, dividing them evenly, then sprinkle with the green onions. If desired, top each bowl with a halved soft-boiled egg and serve right away.