Put the chicken stock, potato, carrot, onion, gochujang, sugar, soy sauce, chilli and garlic in a large pot and bring to a boil. Simmer for 20 minutes until the potatoes and carrots are tender.
Dry the chicken with kitchen towel then cover with the flour and salt. Heat the oil in a large pan or griddle over a medium high heat. Place the chicken in the oil and weigh down with something heavy like a cast iron skillet. Cook for 10 minutes then flip and cook the other side for 5 minutes until cooked through.
Rest the chicken on a plate for a couple of minutes then slice. Serve the stew over rice, topped with the chicken and some chopped spring onions and sesame seeds.