Spread the cubes of bread out on a baking sheet and allow them to dry overnight. Preheat your oven to 350 F. Heat the All-Clad 5 qt. Sautee over medium high heat and add the canola oil to the pan. When you see faint whips of smoke, add the onions. Allow the onions to caramelize then reduce the heat to medium. Continue cooking and stir occasionally. Periodically deglaze the bottom of the pan with a little bit of the water to release the caramelized glaze then allow the glaze to re-form. This process will develop both the color and sweetness associated with French onion soup. Continue the process until the onions have reduced significantly in volume, are very soft and have a deep mahogany color. Add the beef stock, vinegar and salt then remove from heat and allow to cool slightly.