Put all the marinade ingredients into the food processor (except for the meat!) Process until smooth. Pour over the ribeye. Store in the fridge and allow to marinate a couple hours or overnight. Cook the meat at a very high heat on a grill, in a grill pan, or in a skillet, in batches to brown well. Set the meat aside to use in the mac and cheese.
Bring pasta cooking water to a boil. Preheat the oven to 350.
In a dutch oven or heavy bottom sauce pan, melt the butter and stir in the flour. Stir well and cook about 3 minutes until the flour lightly browns.
Whisk in the milk and bring to a simmer, whisking constantly to avoid burning and eliminate clumps. Once it starts to simmer you will notice it has also thickened. Remove from heat.
Drop the pasta into the boiling water and stir well. Cook until it is al dente, about 2 minutes less than the package directs. When the milk mixture has cooled for about 5 minutes, add in the cheeses and stir well until the cheese is mostly melted. Add the cooked pasta into this mixture right after you strain it. Finally add the cooked bulgogi and the chopped kimchi.
Transfer to a baking dish or the stone pots, and bake for a half hour. Top with additional kimchi before serving.