If you purchased a frozen duck, make sure it’s completely defrosted in the refrigerator for a couple of days. Then remove it from the refrigerator about 30 minutes before cooking to bring it closer to room temperature.

Pre-heat the oven to 350 °F (175 °C). Prepare a large roasting pan with a rack so the duck is elevated and fat can drip beneath.

Remove the giblets from the duck cavity (if present). Rinse the duck inside and out with cold water; pat thoroughly dry with paper towels.

Set the duck on the working surface. Score the duck's skin on the breast in a diamond pattern, ensuring you only cut the skin, without reaching the meat. Poke the other fatty parts of the duck with the tip of the knife all over, to ensure fat release, especially in very fatty parts. You don’t need to poke the duck legs as the skin is pretty thin there (except where the duck legs connect to the duck body). Season generously with salt inside the cavity and all over the skin, legs and exterior. Place the duck breast side up.

Place the chopped garlic cloves and lemon slices inside the duck cavity (these are just for flavor, not for eating - you will discard them after cooking). The duck will have flapping skin on both ends - fold that skin inwards, to hold the garlic and lemon inside. Tie up the duck legs with butcher's twine (or aluminum foil if twine is unavailable).

Roast for 40 minutes. Place the duck breast-side up on the prepared rack in the roasting pan. Roast uncovered at 350 °F (175 °C) for 40 minutes.

Flip the duck so it’s breast-side down, and continue roasting uncovered at 350 °F (175 °C) for 20 minutes. After 20 minutes of roasting, check the duck's internal temperature with an instant meat thermometer. If the temperature reaches 140 F, proceed to the next step. If the meat temperature is below 140 F, roast the duck for 10 or 20 more minutes or until the temperature reaches 140 F.

Remove the roasting pan with the duck from the oven, careful not to spill the juices (fat) in the roasting pan. Transfer the duck to a platter, and carefully pour off the rendered duck fat from the roasting pan into a heat-proof container.

In a small bowl, combine ½ cup balsamic vinegar + the juice of 1 lemon + ¼ cup honey. Place the duck breast-side up again on the rack in the roasting pan. Brush all over the duck (especially the scored breast) with the balsamic mixture. Return it to the oven at 350 °F (175 °C) and roast for 20 minutes, brushing every 10 minutes with the glaze.

Roast for another 20 minutes at 350 °F (175 °C), brushing every 5 minutes with the honey-balsamic glaze.

You can carefully broil the duck for about 5 or 10 minutes (check it regularly to ensure it doesn't char too much).

Remove the duck from the oven once the internal temperature reaches ~155 °F (68 °C). Let it rest, uncovered, on the kitchen counter for ~15 minutes.

Carefully remove and discard the lemon from the cavity. Carve the duck and serve!