Prep all ingredients per the instructions above.
Marinate the beef: In a bowl, mix soy sauce, brown sugar, honey, rice wine vinegar, sesame oil, garlic, and scallions. Add the beef and massage the marinade into the meat. Set aside for 30 minutes or longer if preferred.
Cook the rice: Rinse the white rice under cold water. Cook according to package instructions. Once tender, season with salt and pepper. Cover to keep warm.
Prepare the braised potatoes: In a bowl, mix soy sauce, rice wine vinegar (or mirin), garlic, sugar, and water. In a nonstick pan, heat the vegetable oil over medium-high heat. Sauté the potatoes for 4–5 minutes until golden.
Pour the sauce over the potatoes. Simmer until fork-tender but not mushy. If too watery, increase the heat and reduce the sauce until caramelized. Set aside.
Cook the beef: Heat a large skillet or nonstick pan over medium-high heat. Remove beef from the marinade and set marinade aside.
Strain the marinade into a saucepan and bring to a simmer. Stir in the dissolved cornstarch a little at a time until thickened. Remove from heat and set aside.
In the hot skillet, add olive oil and sauté the onion for 2–3 minutes. Add the beef in batches and cook until lightly browned on both sides. Avoid overcrowding to prevent steaming.
Pour the thickened marinade over the cooked beef and set aside.
Garnish the potatoes with sesame oil and sesame seeds.
Serve the bulgogi with rice, kimchi, braised potatoes, and coconut water.