Remove the duck from the fridge 30 mins before cooking to allow it to come to room temperature. Before cooking pat down the skin with a paper towel and generously salt the skin.

Place the duck skin down on a cold cast iron pan and then place on medium heat, this allows for the fat to render. Leave on heat for 5 mins.
Add in the garlic, onion and carrot to the pan, cooking for a further 2 mins. Turn the duck over and then add in the red wine, stock, thyme, salt and pepper. Cook for a further 6 mins (or until duck is 68°C inside). Remove the duck and cover with alfoil to allow it to rest. Add in the lentil to the pan and bring to a boil, then reduce to a simmer for 10 mins.

Slice the duck and serve on a bed of lentils.