1. Heat oil in a six- to eight-quart pot sprayed with cooking spray. Add the onion and the two sliced cloves of garlic and sauté for one minute. Season the meat with kosher salt and pepper and add it to the pot. Sear for a few minutes on each side (see tip below).
2. Meanwhile, in a small bowl, make a paste of the lemon juice, mustard, four cloves garlic, onion soup mix, and thyme. Smear all over the seared roast.
3. Fill the same bowl three-quarters of the way with water and pour it around the meat (the water should go less than halfway up the roast). Add the wine. Bring to a boil; lower heat and cook the meat for at least three hours (I like my meat very tender and cook it for three and a half hours), rotating every hour.
4. Towards the end of the cooking time, prepare the glaze: Place all the glaze ingredients in a small pot and bring to a boil. Simmer for eight to 10 minutes, until thickened and syrupy.
5. Meanwhile, preheat oven to broil. Remove the meat from the gravy and place in a 9 x 13-inch (20- by 30-centimeter) pan. Brush the glaze over the top and sides of meat, pouring the excess all around. Broil for five minutes, basting halfway through. Remove from oven. Cool before slicing.
To sear meat successfully, the meat should be room temperature. Pat dry with a paper towel. Heat a pan with a splash of oil until very hot. Season the meat right before you add it to the pan. Then place it in the pan starting with the edge closest to you, laying it down towards the far edge. This prevents the hot oil from splattering in your direction. Cook the meat and wait until it releases easily from pan before turning it to the other side. Cook an additional minute on the next side before checking it again.
I tried this recipe both with the chestnut jam in the glaze and without it. The jam adds exquisite taste and an elegant dimension to the meat that qualifies it for the most discerning palate. If you can’t find chestnut jam, sub with a handful of blended prepared chestnuts and one tablespoon of brown sugar, added to the other glaze ingredients in the last few minutes of cooking time. The taste will be similar, though not identical.