I cooked this mixture in our rice steamer, and it was fantastic. You can alter the grains to suit yourself, or make real steel cut oatmeal by following the simple instructions at the link.
1/3 c steel cut oats
1/3 c mixture of oat groats, millet, quinoa, and barley
2/3 c water
2/3 c milk or soy milk
Fruit, nuts, additional milk
Steam for 55 minutes. Stir in fruit and nuts when finished and top with more milk.