Preheat the oven to 140°C and place the rack in the middle of the oven.
Remove the turkey legs from the fridge and top with salt and pepper. Set aside.
Chop the vegetables (carrots, celery, leek, onion). Melt the butter in a pan over medium heat and add the vegetables, herbs and crushed garlic. Sautee until it becomes nice and soft. Add a little bit of boiled water and the bouillon cube, and let it stew for a few more minutes.
Put the vegetable mixture in the roasting pan and set it aside.
Heat the oil in another pan over medium heat and add in the turkey legs. Be careful not to crowd the pan. Fry the turkey legs in the pan for about 5 minutes each side until it is golden brown.
Place the turkey legs on top of the vegetable mixture and let it rest for a few minutes so that the turkey would absorb the flavor from the mixture.
Place the turkey in the oven and roast uncovered for 2 – 2 1/2 hours, until the meat is tender and falling from the bone. When it is done, remove from the oven. Transfer the turkey legs to a dish, covered with foil, and let it rest.
For the gravy, you’ll need the pan juices, so strain the vegetable mixture and discard the vegetables. Add the juices to a saucepan over medium heat, and then add the wine. Let it boil to remove the alcohol. Add the lemon juice and brown sugar, and then mix in the cream.
If you’d like to make the gravy thicker, add some flour and whisk continuously to the desired thickness then remove from heat.
Now you are ready to put your turkey leg on the plate, covered in the delicious gravy, and sprinkled with chopped rosemary.