Preheat oven to 325°F
In a medium bowl, whisk together orange juice, soy sauce, white miso paste, ginger paste, honey, rice vinegar, mashed garlic, black pepper, and red chili flakes to make the marinade
Pat dry the chuck roast and place it in a dutch oven
Pour the marinade on top and flip the meat a few times to coat it well
Cover with a lid and place in the oven for 3 ½-4 hours
At the 3 ½ hour mark, pull the meat out and use two forks to shred it
If the meat is not easily shredding, pop it back in the oven for 30 minutes more
Once ready, remove from the oven and shred all the meat, tossing with the juices
Optional: For crispy bits, place the pot back in the oven under the broiler on high for 3-4 minutes
Remove and serve
