Step 1

In a large (10 to 12-inch) saute pan, cook the butter and onions over medium-low heat for 12 to 15 minutes, until the onions are lightly browned. Don't rush this step; it makes all the difference when the onions are well-cooked.

Step 2

Sprinkle the flour into the pan, whisk in, then add the salt and pepper. Cook for 2 to 3 minutes. Add the hot chicken stock mixture and Cognac, and cook uncovered for 4 to 5 minutes until thickened. Add the wine and cream, if desired. Season, to taste, and serve.