How to Make It
Using a paring knife, make 8 incisions all over the pork roast. Roll up the sage leaves and press each one into an incision. Rub the roast all over with olive oil and lightly sprinkle with salt. Let marinate at room temperature for up to 2 hours.
In a small saucepan, simmer the lemon zest, juice and sugar over low heat, stirring, until reduced to 1/4 cup, about 20 minutes; strain the syrup.
Heat 1 tablespoon of the olive oil in a medium saucepan. Add the pork bones, season with salt and pepper and brown over low heat for 10 minutes; discard the fat. Add 2 cups of the stock and simmer until reduced by half, about 30 minutes. Add the remaining 2 cups of stock and simmer until reduced to 1 cup, about 30 minutes. Add the sage sprigs and simmer until reduced to 1/2 cup, about 20 more minutes; strain.
Preheat the oven to 300°. Heat the remaining 1 tablespoon of oil in an ovenproof skillet. Add the pork, fat side down, and brown over moderate heat for about 10 minutes; discard the fat. Turn the pork fat side up and roast for 30 minutes; baste twice with the lemon syrup. Roast for about 15 minutes, basting with the pan juices, until an instant-read thermometer inserted in the center registers 145°. Let the roast rest for 10 minutes.
Reheat the sauce and season with salt and pepper. Carve the roast and serve with the pan sauce and Duet of Cauliflower.