Just listening to parts of this OST for first time, still haven't seen das Finale 1-3 because I've been waiting for the dub... but I've been waiting years and it could take several more years at this rate (since 4-6 have yet to release yet) so I may very well just watch the sub for now because the temptation grows.
But anyway, I came to this track and now it's probably one of my favourite renditions of La Chanson de l'oignon now, a French military song originating from the Napoleonic Wars... about how much the French love their onions.