It is easy to do a decent job of breasting a duck—and just as easy to hack the thing to pieces. So you take your time. Use a sharp knife, one with flex to the blade. Hold it flush against the keel of the breastbone, to free the pectoralis minor muscle, the “tender,” in one piece. Angle the tip under the wishbone to capture the full length of the breast. Leave no flesh behind. Done well, the breastbone and wishbone are a gleamy, creamy white, smudged with no more than a smear of blood and meat. And in your hand is a complete fillet, a gift from the marsh gods, and a testament to your skill with both gun and knife.