Rinse the 300g of rice in several changes of cold water until the water runs mostly clear, then drain well. Cook it in a rice cooker, or in a covered saucepan with water at your usual ratio for the rice, ideally while the chicken marinates so it is ready when the pan is. Rest it covered for 10 minutes, then fluff gently with a fork and keep it warm. The grains should stay fluffy and distinct, never sticky or wet. That covered rest is what lets residual steam settle evenly, keeping the rice genuinely separate enough to sit beneath a sticky glaze without turning to paste.

In a large bowl, stir together the 4 tbsp gochujang, 1½ tbsp gochugaru, 2 tbsp soy sauce, 1½ tbsp brown sugar, 1 tbsp honey or corn syrup, 1½ tbsp mirin or rice wine, 1 tbsp sesame oil, 4 grated garlic cloves, 1 tsp grated ginger, ½ tsp black pepper, and 2 tbsp water. Mix until completely smooth, with no streaks of paste. The sauce should be genuinely thick but spoonable, clinging to the back of a spoon rather than running off it. That thickness is what lets it coat the chicken evenly now and later reduce into a glossy glaze rather than a thin, watery sauce.

Cut the 700g of chicken thighs into large bite-size pieces so they stay juicy in the pan, add them to the sauce, and toss until every piece is evenly coated. Cover and leave for 20–30 minutes, refrigerating the bowl if the wait will run longer, and use the time to cook the rice and prepare the vegetables. The chicken should look deep red and fully coated. That short marination is what lets the meat take on colour and flavour before it touches the pan, so a longer wait is fine but not necessary.

Peel the 300g of sweet potato and cut it into small bite-size chunks or thin half-moons, then slice the onion, cut the 300g of cabbage into rough bite-size pieces, and cut the 4 scallions into 4–5 cm lengths, keeping the whites and greens apart. If the sweet potato pieces are on the thicker side, microwave or steam them for 3–4 minutes until just starting to soften but still holding their shape. That head start matters because sweet potato takes the longest of all the vegetables, and pre-softening is what lets everything finish together without overcooking the chicken.

Heat a wide sauté pan or skillet over medium-high heat with the 1½ tbsp neutral oil. Add the marinated chicken in one layer as much as possible, scraping in all the sauce from the bowl, and leave it largely untouched for 4–5 minutes until the outside is browned and lightly caramelised. Lower the heat slightly if the sauce darkens faster than the chicken colours, and do not stir constantly at the start. That steady contact with the hot pan is what builds caramelised flavour, since constant stirring or a crowded pan lets the chicken steam instead of sear.

Add the sweet potato, onion, scallion whites, and cabbage to the pan and toss everything together with the chicken. Add 2–4 tbsp water if the pan looks dry, then cover for 3–4 minutes. Uncover and keep cooking, stirring often, for another 8–12 minutes, until the chicken is cooked through to 74°C in the thickest piece, the cabbage is wilted but still present in pieces, the onion is soft, and the sweet potato is tender when pierced. That covered start is what steams the vegetables through, and the uncovered cooking afterwards is what lets excess moisture cook off instead of pooling like a stew.

Add the scallion greens and cook for 30–60 seconds more, stirring until the sauce turns glossy and clings tightly to the chicken and vegetables. The mixture should look thick and shiny, with no thin liquid pooling in the pan; if any remains, keep cooking over medium-high heat for another minute or two. The vegetables should be tender and glazed, not watery. That final reduction is what genuinely turns a loose sauce into a lacquer, which is the difference between dakgalbi and a spicy chicken stew.

Divide the hot rice among 4 bowls, then spoon the dakgalbi mixture over the top, leaving some white rice visible around the edges. Scatter the 2 tsp of toasted sesame seeds and the thinly sliced extra scallion across the four bowls. Serve straight away, while the glaze is hot and sticky and the vegetables are still tender. That visible rice border is what keeps the dish eating like a rice bowl, with the glaze seasoning only the first layer of grains instead of soaking the whole base.