Heat the oven to 350°F. Trim the pork and make a horizontal slit in the meat, cutting almost through to the other side. Open the meat flat, like a book, so it's an even thickness.
Stuff 4 to 6 of the apricots with almonds and wrap each apricot with a prune. Lay the prunes along the center of the cut surface of the pork, adding more stuffed fruit if needed. Roll the pork up so that it forms a tight cylinder. Tie the roast at 1-inch intervals. Sprinkle it on all sides with salt and pepper. Coarsely chop the remaining prunes and apricots.
Heat the butter and oil in a Dutch oven over medium-high heat and brown the pork thoroughly on all sides, 8 to 10 minutes total. Take out the pork, add the onion, and sauté until it starts to turn brown, about 3 minutes. Stir in 1/2 tsp. pepper, the thyme, cinnamon, cloves, and nutmeg and cook, stirring, until fragrant, 1 minute. Add the vinegar and simmer 1 minute. Add the wine and simmer until it’s reduced by almost half, 10 to 12 minutes. Stir in the chopped fruit and the stock or broth. Replace the pork, pushing it down into the sauce, cover the pot, and bring to a boil.
Put the pork in the heated oven and cook, basting with the pan juices and turning occasionally, until an instant-read thermometer inserted in the center of the meat registers 145°F, about 45 minutes. If the sauce reduces rapidly during cooking, add more broth. When the pork is done, the sauce should be dark and reduced by about half with a slightly thick consistency; if it’s thin, remove the meat and reduce the sauce by simmering it on the stovetop.