Whisk together the gochujang, palm sugar, sesame oil, and 2 teaspoons of the rice wine vinegar in a medium bowl and set aside.
Pulse the meat 8 to 10 times in the bowl of a food processor or until it resembles a medium grind. Combine with the gochujang mixture and refrigerate for 30 minutes.
Stir 1/2 cup of the kimchi together with 1 tablespoon of the vinegar, all the ketchup, and fish sauce and set aside.
Whisk the eggs with the soy sauce until homogenous.
Heat a large saute pan (or wok) over high for at least 5 minutes, then add 2 tablespoons of the peanut oil followed by the mushrooms and 1 teaspoon of the salt. (Don't overcrowd the pan; they should only be one layer deep -- you may have to do them in batches) Sear, undisturbed for a minute and a half then stir and continue cooking until they develop well browned, crispy edges, about 2 minutes. Remove the mushrooms from the pan and drain on a paper towel. (If you have to do the mushrooms in batches, add a tablespoon of oil to each addition.)
Add 1 tablespoon peanut oil to the pan followed by the garlic, ginger and remaining teaspoon of salt. Count to three, and then add all the meat and marinade and saute until cooked through, about 5 minutes. When the pan is almost dry, add the kimchi mixture to the pan and stir, scraping up any browned bits stuck to the bottom of the pan.
Stir the spinach into the pan and cook for one minute followed by the eggs. When just set, fold in the scallions and immediately transfer to a large serving bowl and set aside while you fry the rice.
Heat the remaining 2 tablespoons of the peanut oil over high heat just until it shimmers. Add the rice to the pan, mashing it into a thin layer, and cook undisturbed until you hear it start to crackle, about 5 minutes. Stir in the remaining 1/2 cup of kimchi and cook one minute more, just to heat through. Portion into 4 bowls, top with the scramble, and garnish with sesame seeds.