Feel free to leave out the cheese if you want an unadulterated onion dip experience. Some of you will remember this recipe from my Dips article in Bon Appitit (March 2001). It's worth repeating.
PRESENTATION SUGGESTIONS:
Serve atop and alongside Grilled Steaks, as the French do. I would pass the extra sauce in a silver or glass sauceboat or pitcher for guests to take more.