3 tablespoons butter
1 leek, white and light green part only, sliced
1 cup diced bacon
1 shallot, chopped
1/2 cup flour, sifted
6 cups low-sodium chicken broth
2 tablespoons Red Duck Sweet Mustard Peppercorn BBQ Sauce
1 tablespoon grainy mustard
1/2 cup heavy cream
Salt and freshly ground black pepper to taste
Chives, for topping

In a large skillet over medium heat, heat up the butter until melted. Add sliced leeks and saute until soft, 3-4 minutes, stirring often. Set aside.

In a large saucepan over medium-high heat, cook bacon pieces until crispy. Remove and drain on paper towels, and drain off all but about 2 tablespoons of the fat (if your bacon was lean and there isn't that much fat in there, add some butter). Return to heat and add shallots. Saute until soft and translucent, 2-3 minutes.

Then, working quickly, add about half the flour to the shallot mixture and whisk to make a smooth roux. Add a bit of the broth and whisk to incorporate, then add rest of flour, followed by enough broth to make the mixture nice and smooth. Add the rest of the broth, followed by the Red Duck Sweet Mustard Peppercorn BBQ Sauce and the mustard. Lower heat and, whisking frequently, bring the mixture to a simmer. It should be thickened and bubbly. 

Add the cream, season to taste with salt and pepper, and serve immediately, topped with sauteed leeks, bacon, and chopped fresh chives. Serves 4.

Adapted from about.com