Chop a bag of onions, toss with melted butter and leave, covered, in a 300 F (150 C) oven overnight to quasi-caramelize them. The next evening, mix these with a few cups of porcini mushroom broth (I used this because it was on hand and much better made from cubes than any beef broth that is cube-based). Add salt and pepper to taste, let it simmer for a little while. Top with a crouton, grated cheese (I used a partially aged gouda) and broil until brown on top. Serves a few. Way fast and easy!
Possible enhancements: The onions only get quasi-caramelized, not fully caramelized, because the closed pot doesn't let them dry out as much as they should; PMC suggests lowering the heat but leaving them in uncovered. Worth a shot! Alan Mooney suggests adding sherry to the broth. Duh!
