Step 1. Place the frozen beef roast into the Crock Pot and set it depending on how much time you have to cook the roast. If you plan on cooking for eight to nine hours, set the crock pot to low.If you only have four to five hours, set the crock pot to high.tep 4. Place the lid on the Crock Pot and turn it on. There is no need to turn the meat. Since the lid traps some of the steam for cooking purposes, avoid opening the crock pot to check for doneness. Set a timer for the amount of time the roast needs according the heat level.