Heat 1 can of broth in microwave(in a microwave-approved container, of course) for a couple of minutes. Add to empty crockpot and dissolve the onion soup mix in it. Add remaining ingredients, except herb mix, to crockpot, reserving 1/2 can of broth. Cover and cook on low for at least 6 hours. 1 to 2 hours before ready to eat add the herbs that have been crushed together with a small pinch of sea salt to the soup mixture. (If you add this at the beginning the soup will be bitter!) Also, at this stage if the soup needs more liquid, add the remaining half-can of broth. This is a thick, hearty soup, but barley can be just like rice, one day needs a little more liquid, another, a little less. Leftovers freeze well, though there are rarely any here.
Sometimes I will substitute or add little bits of frozen veggies from cleaning the freezer, like a cup of corn or green beans or carrots to the mix. If adding instead of substituting, you may need to make adjustments to your broth amount.