I recently tried a new recipe which involved cooking vegetables at a lower temperature than I normally see. I had problems with the instructions from the start. The low setting on my stovetop didn't seem to do the trick to sweat the onions or simmer the soup until I turned it up to medium first.
As a result, I spent a lot of time waiting, and the soup spent less time at any kind of boil. The resulting soup doesn't have much flavor despite the ingredients all being fresh.
Could it be that the vegetables didn't get hot enough for long enough to do the job? How do I fix it?