A bolognese-type sauce recipe I usually do uses ground beef, canned tomatoes, onions, carrots, chilli, garlic and bay leaf. The bay leaf gets cooked with the rest for a while and the sauce tastes wrong if I forget to put it in.
Now my question is, does the bay leaf do anything specific, like sugar counters the acid from tomatoes, or is it purely that the taste becomes unfamiliar and thus feels incorrect?