I just bought some "jab gok bap," which I think is the name for this amazing mix of rice, beans and grains. What I have is Assi brand and it's called Mixed Grains in English.
I tried cooking it from one recipe I found, but it turned out a smushed-up mess. Tasty, but very unattractive to look at. Yikes! You are supposed to soak it for a long time first, then cook it ... but that's where I think I went wrong, in the timing.
The package says to use a rice cooker, but it doesn't give any proportions for grain to water or times or settings, etc.. I don't have a rice cooker right now, though I will probably be getting one soon.
I would love to be able to cook this so it doesn't get all mushy. Is that possible? Several of the recipes I found added water chestnuts and dates and other sweets. Not really my favorite way to go, but I will try it at least once if there is some authentic Korean way to serve it.