Mustard and Rosemary Pork Loin with Apple Gastrique

Line a sheet pan or a 12- by 16-inch roasting pan with a wire rack.

In a small bowl, stir together the mustard, rosemary, garlic, salt, and pepper. Give the pork loin a serious rub down with the seasoning mix, making sure to coat all of the sides. Place on the prepared pan and insert the probe in the center of the pork.

Transfer to the oven, attach the probe, and cook until the probe reaches its target temperature, 2 to 3 hours. (The total cooking time depends on the thickness of the pork loin.)

While the pork is cooking sous vide, start the apple gastrique. Combine the apple and honey in a small saucepan. Place over medium heat and bring to a simmer. Continue to cook, stirring very frequently, until the honey has mostly evaporated and the apples look caramelized, about 6 minutes. Stir in the vinegar and bring to a simmer. Add the apple cider. Bring back to a simmer, then continue to simmer until the cider has reduced by half, about 7 minutes. Remove from the heat and set aside while the roast finishes cooking.

Remove the pork from the oven before adjusting the settings.

Carefully decant the drippings from the bottom of the pan and reserve for the sauce. Once the oven is heated, return the pork to the oven and cook until browned, 3 to 7 minutes. Remove from the oven and let rest while you finish the sauce.

Return the sauce to a simmer over medium heat. Stir in the pork drippings, about 1 tablespoon at a time, until the sauce is flavorful and well seasoned. Stir in the horseradish, if using. Remove from the heat.

Remove any butcher’s twine from the pork, slice, and serve with the apple gastrique.