Step 1

Score the duck’s skin with a cross-hatch pattern, making sure not to pierce the actual flesh underneath. Season both sides with salt and place, skin-side down, in a cold skillet. Turn on the heat to medium-low and let cook on the skin side 10 to 15 minutes, until much of the fat has rendered out. Flip and sear the other side 2 minutes, or until internal temperature of the meat is 135°F, medium-rare. Set aside to rest while you make the pan sauce.

Step 2

Pour the duck fat out into a glass or ceramic container (save that for potatoes another day), leaving about 1 teaspoon behind. Sauté the white parts of the scallion 1 minute, seasoning with salt. Splash in the Port and frozen blueberries and let reduce until very syrupy, about 10 minutes. Add the vinegar and fish sauce and let warm through for a few seconds. Take off the heat and add the pat of butter, moving it around constantly until fully melted and sauce is glossy.

Step 3

Transfer sauce to a plate. Carve the duck breast into thin slices and lay over the sauce. Garnish with the green parts of the scallion and freshly ground black pepper. Eat with roasted potatoes or a side salad, like frisée or radicchio.