Foolproof Lentil Barley Soup

I'm almost embarrassed to post this, because it is so extremely easy. But our friends who were here to eat it with us asked for the recipe, because they liked it so much. Alas, I can't remember where I found it, so I can't give credit where credit is due, but it is a wonderful soup. I made it twice last week, and would have made it again if I hadn't run out of lentils and barley. So it also helped in the pre-Pesach pantry purge.

The actual recipe went like this:
1 cup lentils, rinsed and picked over
1/2 cup barley
1 onion, diced
2 cloves garlic, minced
2 stalks of celery, sliced
2 carrots, thinly sliced
6 cups vegetable broth (I ended up using much more)
1/2 tsp oregano
1/2 tsp cumin
salt and pepper to taste

Put all ingredients in large pot. Bring to a boil. Reduce to simmer. Simmer one hour, stirring occasionally. Eat.

This soup is very forgiving. It was incredibly thick -- I ended up pouring in several additional cups of broth, and water when I ran out of broth. The second time I made it, I threw in an entire bag (about 1 lb?) of "frozen vegetables for soup" that included potatoes, lima beans, okra (I guess I know I live in the South now because the soup vegetables include okra?), corn, and some other stuff -- it was still great. I'm also pretty sure that the second time I made it I forgot the cumin and added basil -- that worked, too. Enjoy it, now and next winter.