Place a large cast-iron skillet over medium-high heat and add the diced pork belly.
Sauté the pork belly until the fat renders and the meat becomes crispy and golden brown.
Remove all but one tablespoon of the rendered fat from the skillet.
Add the minced garlic and grated ginger, stirring for 30 seconds until the aroma is released.
Stir in the chopped kimchi and cook for 2 minutes until it begins to caramelize.
Add the chilled jasmine rice to the pan, using a spatula to break apart any clumps.
Pour in the kimchi juice, gochujang, and tamari, tossing the rice until it is thoroughly coated and heated through.
Push the rice to one side of the skillet; crack the egg and pour the egg white onto the cleared space, cooking until the white is firm and the yolk is still runny.
Turn off the heat and fold in the sliced green onions and toasted sesame oil.
Transfer the rice to a bowl, top with the fried egg, and sprinkle with sesame seeds, sea salt, and black pepper.