Bernard's Fave French Onion Soup ala Vivienne

Steps

1. Warm the butter and olive oil mix over medium heat. Sautee the thinly sliced onions. Stir over medium heat until the onions are VERY brown but not TOO brown (aka burned). This carmelization step is key to the good soup. Also, if you want a little garlic, add it near the end of this step.
2. Once the onions are very brown, stir in dijon, thyme, worceister for one minute
3. Add the broth of choice -- generally enough to cover onions plus about two inches -- beef broth will give you the authentic french restaurant flavor, but we often use chicken or veg broth, and then adjust to taste the additives (dijon, worceister, vinegar, etc)
4. Bring to boil, then simmer for...hmm...30 mins plus?
5. Check the broth and add salt and white/black pepper to taste.
6. A final step on the broth is to add "brightness" - this can be apple cider vinegar (preferred), sherry (very traditional) or another vinegar (white or red) or even a splash of dry wine (red or white, must be dry). To be safe, just add a little (like 1 tsp), taste and taste again until you like the effect.
7. You can also re-taste and adjust anything - salt, pepper, brightness, mustard, worcestier, etc.
8. Options for serving - traditional is to float baguette slices in the soup, in oven proof bowls, slather with grated gruyere cheese, and broil until the cheese is browned and bubbly. Easy home cheat is toast baguette slices with the gruyere in toaster over, and then float them in the hot onion soup.
9. Sprinkle with fresh thyme and/or parsley, black pepper, and serve!