This sauce is particularly nice with game birds. To turn this into a true Bigarade Sauce for duck or goose, use the zest and juice from a Seville (bitter) orange and omit the lemon juice.

With a fork, mash together in a small bowl until combined:

Set aside. Using a vegetable peeler, remove strips of zest from:

Cut the zest into slivers about ⅛ inch wide and 1 inch long. Place the zest in a small saucepan, add 4 cups cold water, and bring to a boil over high heat; cook 1 minute. Drain the zest in a sieve, rinse with cold water, and pat dry.

Transfer the roasted bird(s) to a platter and keep warm. Pour off the fat from the roasting pan. Pour into the pan:

Set the pan over medium heat (on 2 burners if necessary) and bring to a simmer, scraping the pan bottom with a wooden spoon to dissolve the browned bits. Remove the pan from the heat and set aside. Combine in a small heavy saucepan and cook over medium heat, stirring, until a light brown, caramel color:

Add the contents of the roasting pan and simmer for 5 minutes. Whisk in the orange zest along with:

Bring to a simmer, stir the softened butter and flour mixture into the sauce, and simmer for 1 minute or until thickened. Spoon the sauce over the bird(s) and garnish with: