In a slow cooker, combine the pork shoulder, chicken broth, water, soy sauce, miso paste, sesame oil, ginger, garlic, brown sugar, and red pepper flakes (if using). Stir to combine.

Cover and cook on low for 8 hours or on high for 4 hours, until the pork is tender and easily shreds with a fork.

Once the pork is cooked, remove it from the slow cooker and shred it using two forks. Return the shredded pork to the broth in the slow cooker.

In a separate pot, cook the ramen noodles according to package instructions. Drain and set aside.

To serve, place a portion of ramen noodles in a bowl, ladle the pork and broth over the noodles, and top with baby spinach, sliced green onions, and a soft-boiled egg if desired. Garnish with sesame seeds if using.

Enjoy your delicious homemade pork ramen!