Step 1

Set up an immersion circulator and preheat the water bath to 155°F (68°C).

Step 2

Season duck all over with salt and pepper. Rub garlic onto the meaty side of each leg and set a thyme sprig on top. Slide duck legs into vacuum bags and seal according to vacuum-sealer manufacturer's instructions.

Step 3

Add sealed duck to water bath and cook for 36 hours. Make sure to top water up occasionally as it evaporates, and keep bag completely submerged. If bag floats, weigh it down by placing a wet kitchen towel on top of it.

Step 4

Remove duck from water bath and transfer to refrigerator to chill. The duck can be kept refrigerated within the sealed bag for up to 1 week.

Step 5

When ready to use, remove duck from bag and scrape away thyme sprigs and excess fat and juices. Use duck confit according to any recipe you have; it can be cooked in a 450°F (230°C) oven or broiled until the meat is heated through and the skin is browned and crispy, about 7 minutes.