The phrase "entire roast" means to cook a whole piece of meat, typically referring to a large cut like a whole chicken or a beef roast, instead of cooking smaller portions. Full definition
As I see it, I can enjoy three entire roasted beets, meet more than 15 % of my iron requirement, and prevent cancer — all with a root crop that is extremely easy to grow in my garden, and that kids actually enjoy eating. (ethicurean.com)