Based on the previous reviewer's comments, I cut down the proportions of this recipe to fit in my 4-quart crockpot. I used 2 good-sized sweet potatoes and half of a large can of tomatoes. I initially put in only enough water to cover (about 3 cups), but I needed to add more water halfway through since the barley soaked up most of that. I felt like it needed some kind of seasoning but I'm not sure what -- it turned out kind of bland. It's one of those dishes that's definitely better once it has cooled a bit.
I really wanted to like this recipe, but unfortunately, it wasn't as good as I expected. The amount of seasoning was not sufficient, so it came out a little bland, and I didn't care for the tomato/sweet potato flavor combo. If you do make this, use a very large crock pot. I had to reduce the amount of several ingredients and it still overflowed in my 4 quart pot.