Clean the meat of tallow remains and then rub it with salt and pepper. Heat the pan and put in 1 tablespoon of olive oil. When the oil is hot, place into it the meat. Crust both sides. Use a cast iron skillet with a heat resistant handle if possible, which you can later place in the oven.
When the meat has a golden brown crust, remove it from the skillet and let it rest while you fuse the remaining oil with the rosemary and the 2 cloves of garlic in the skillet. Pour on the red wine and cook it until the alcohol has evaporated.
Place back into the skillet the meat larded with the rosemary and 3 cloves of garlic cut into thin slices, and pour on the broth. Add the fresh thyme, too.
Wait until it starts boiling, then cover the skillet with the lid or with an alufoil and place it in the oven. Bake it at 170 C for 2 hours and then for another 30 minutes without the cover. Make sure you turn the meat over and then back, splashing it when necessary. Taste it and add salt or pepper accordingly.
In the meantime, prepare the orange-mustard glaze. In a warm pan, mix the brown sugar with the apple balsamico mustard and the juice of the orange. Boil it until you get a sauce of honey consistency.
After you remove it from the oven, spread the orange-mustard glaze over the lamb, and lard it with the orange slices and cloves. Bake it for another 20 minutes at 180 C for 20 minutes, without covering it.
After the meat is done, cool it at room temperature for 10 minutes. During this time, the moisture will disperse evenly, making the meat juicier and easier to slice.