4 small or 2 large boneless duck breasts (1-3/4 to 2 lb. total)
Kosher salt and freshly ground black pepper
1-1/2 Cups seedless purple or red grapes
1/4 Cup minced shallot
1/2 Cup dry white wine
1 Cup low-salt chicken broth
3 Tbsp Saba Grape Must Reduction
1 Tbsp chopped fresh Italian (flat-leaf) parsley
Use a small sharp paring knife to score the skin on the duck breasts in a diamond (XX) pattern, taking care to not cut through to the meat. Generously salt and pepper the duck on all sides before placing, skin side down, each not touching other breast pieces, in a cold skillet. Bring skillet to medium heat and cook duck breasts, keeping them skin side down. Spoon off and reserve the excess duck fat while cooking over medium heat, until skin becomes a light golden brown, about 8 min.
Gently pry the duck breasts from the skillet with a spatula before raising the heat to medium-high. Keep cooking the duck over higher heat, still skin-side down, about 4 more minutes. Skin will be crispy and browned.
Flip each duck breast piece and cook about ten minutes more. Check for doneness with a meat thermometer inserted into the thickest part of the breast. A medium-rare duck breast will be 135°F – for food safety purposes, keep cooking until at least this internal temperature. Transfer the browned duck from the pan to a plate.
Pour off duck fat from the skillet, leaving 1 Tbsp in the pan. Add the seedless grapes and cook over the same medium-high heat setting until lightly browned, about 3 minutes. (Stir grapes while you cook so that they do not stick.) Use a slotted spoon to gently transfer the sautéed grapes to the serving platter, arranging them around the duck.
Add the minced shallot to the skillet. Cook until shallots have begun to soften, about 1 minute. Add the wine and deglaze the pan, loosening the crispy bits from the bottom of the skillet, until all the liquid evaporates, 2 to 4 minutes. Next, add the chicken broth and Saba to the deglazed pan. Return to a boil and keep stirring intermittently until the mixture is reduced to only 2/3 Cup, about 6 minutes. Adjust salt and pepper to taste.
Return the grapes, duck, (and any yummy juices that were left behind on the platter) back to the skillet. Simmer everything in the pan sauce for a minute or two so that all ingredients will warm through. Make certain that the duck breast pieces are coated with the sauce!
Transfer duck to a cutting board and slice thinly before dividing it among the four plates. Top duck with grapes and Saba sauce, then garnish with fresh parsley and serve immediately.