Here's an easy to follow recipe for the French Onion Soup served at Ocean Prime.

Ingredients
Olive Oil Blend            1.5 oz
Onions ¾” Dice            4 lbs
Scallions, Sliced            2/3 cups
Leeks, white part only, ¾” diced    1.5 each
Shallots, ½” dice            1 cup
Marsala                ¼ cup
Chicken stock                1 gallon
Veal stock                ¼ gallon
Black pepper, #2 grind        1/3 tbsp
Kosher salt                1 ¼ tbsp

Procedure
1. In a heavy bottom pot, place oil and onions on 4 burners with low heat
2. Slowly caramelize onions until dark brown, stirring often
3. Deglaze with Marsala add beef base
4. Add chicken and veal stocks and simmer
5. Adjust seasoning with Kosher salt and black pepper