Salisbury Steak with Roasted Potatoes

russet potatoes 52.3% , water 16.1% , modified corn starch 8.1% , beef 5.0% , cooked beef meat 3.4% , yeast extract 2.5% , beef tallow 1.9% , beef extract 1.5% , flavouring 1.3% , salt 1.0% , sugar 0.9% , vegetable juice 0.8% , E270 0.7% , onion 0.6% , wine 0.5% , E508 0.5% , Rochester sauce 0.4% , canola oil 0.4% , butter 0.4% , garlic 0.3% , black pepper 0.3% , pork 0.3% , textured soy protein 0.3% , oat flakes 0.2% , beef base 0.2% , E508 0.2% , spice 0.2%