Mrs. Phillpott is a cook for the Thornberry family. She usually makes a 5 pound roast for dinner on Thursdays. She knows that it takes 2 1/2 hours to cook this roast. Her boss is having a dinner party and she needs to make more food. She decides that she needs 15 pounds of meat. The problem is that she only has one oven and it will not hold a roast bigger than 10 pounds. How could she solve this problem? (Answer in paragraph form.)