I use rolled oats in my shake - grind them up first to a powder then add everything else (using Magic Bullet).
For steel cut, cooked here is what I make for us:
4 cups water
1 1/4 cups steel cut oats
1 cup chopped walnuts
1/2 cup chopped dates
3 tbsp coconut oil
2 tbsp honey or some maple syrup
dash of salt
Bring water and salt to boil.
Add oats.
Cook for 16 minutes. In the final 3 minutes, add the walnuts, dates, coconut oil and honey.
Let it sit a few minutes.
Add milk to desired consistancy.
I then put into a few bowls for later. So far everyone who has tried it has enjoyed it. I have added whey when eating also. Sometimes a little jam is good too.
Good luck!