Steak & Kidney casserole is a fav in our house, my kids dont even know they are eating the kidney,  i coat meat in seasoned flour, give a quick fry in large pan to brown then put into crock pot,  i also quickly then soften diced onion in the same pan, add two cups beef stock, a couple of tablespoons of worcester sauce and a table spoon or two of mustard (or 1 teaspoon mustard powder) then pour over meat and slow cook 7 - 8 hours.  my Hubby absolutely goes nuts for this.

you can even cook a sheet of pastry at the end of it and cut into slices so the kids think they are having a pie.