By request from a still sniffly wife, after shoveling the sidewalk I went and got a bunch of big yellow onions. Caramelized to a dark near-sludge, then added some dried porcini, herbs, a glug of wine from last night, soy sauce, sesame oil, and then water to cover the onions. Let it simmer for about 20 minutes, salted to taste and served with chopped scallions and a drop of truffle oil. Wicked.
You don’t need beef broth to make perfect onion soup, or even a cheesy crouton. It’s all about the caramelization, and adding some bottom with the porcini and soy. Nobody would taste this soup, then make a disappointed face and say “Aaaaw- it’s vegan!”