1. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius). Place onions in a large roasting pan. Set aside.
2. Heat a little bit of oil in a large pot and sear meat on all sides for a few minutes. Remove to roaster. Rub with salt and pepper. Spread mustard on the meat.
3. Combine wine, pineapple, oil, cranberry sauce, maple syrup, and teriyaki sauce in a small bowl. Pour over meat. Add approximately two inches of water to the roaster. Sprinkle garlic cloves all around. Drizzle top of roast with date syrup.
4. Cover roaster with Gefen Parchment Paper and then seal tightly with foil (this keeps the meat nice and moist). Bake in oven one and a half to two hours for rare meat and three to three and a half hours for well done. You can also cook the roast in a pot for approximately three to four hours (depending on cut/size), rotating every hour or so.
Refrigerate roast overnight without the gravy. Slice the next day when it has sufficiently cooled. Pour sauce over meat before heating. You can freeze the meat already sliced with just a bit of gravy and freeze the rest of the gravy separately in a container. You can also freeze leftover cranberry sauce for future use.