Place the duck breast on a dish lined with paper towels in the fridge overnight.
Season breast with salt and white pepper and seal in a bag with a vacuum sealer. Place the bag in a 135 degree Fahrenheit water bath for 2 hours.
Remove from water bath and pat dry.
Place the duck breast skin side down on a cold pan and place over medium heat. Once you hear sizzling, increase the heat to medium-high and cook till fat has rendered and skin is crispy (about 5 minutes). Flip the breast and brown the other side for 30 seconds (you just want to get some color not overcook the meat).
Remove from the pan and let the meat rest while you make the sauce.
Leaving only about a tablespoon of fat in the pan, sweat shallot over medium heat. Add the vinegar, port, stock and spices. Scrap the pan and let the sauce reduce by about half. Add the syrup and season with salt and pepper. Once the sauce has thickened and can coat the back of a spoon, add the cold butter.
Strain the sauce, cut the breast in thin slices at an angle and top with the sauce. Enjoy!
Recipe by Swine + Wine at https://www.swineandwine.ca/duck-breast/