I usually just salt and pepper my roasts, then brown them in a big iron skillet, transfer the roast to a big pot with tight fitting lid, your roaster would be fine, and I layer the bottom with slices of onion. Just put the roast in and let it cook at 350 for an hour,then turn it down and let it cook slow at 225 degrees for a couple hours. I am assuming you have an electric oven. When you think it looks about done, you can also put potatoes, carrots around the roast and add some water so it will steam the veggies. If you want to save clean up time, just wrap it in aluminum foil, put in the roaster and bake the same way. I love roast. There are so many ways to use left overs. Some people like to just use Liption Onion Soup and pour over the top and bake, it is good as well. You can't go wrong. The longer it cooks slowly, the more tender it is. If you want to cook without onions, the roast will make juice in the bottom and you can make a great gravy to go over mashed potatoes or noodles.