What sort of roast are you looking for, Di? A pot roast or a fine roast beef?
For a pot roast
, I like to buy a piece of beef chuck roast, or sometimes I buy something called an "English Roast." Generally 3-4 pounds.
I quickly sear or brown this in some olive oil in a skillet on the stove top, then stick it in a slow cooker with some canned stewed tomatoes, some quartered onions, a clove of garlic, a bay leaf and some beef broth and/or some red wine and let it cook all day. Toward the end of the cooking I add peeled potatoes, sliced carrots, etc.
This is a less tender cut of beef, so you need to cook it long and slow. When it's done, the beef will fall apart in the crock pot -- it's that tender.
For a traditional roast beef
, you need to buy something a bit pricier, like prime rib.
You coat this with a paste of herbs and salt and pepper, put it in a roasting pan and cook it in the oven at 350 degrees F. Use a meat thermometer, and it's done when the beef reaches an internal temperature of 125 degrees Farenheit. This will probably take a few hours, depending on the size of the cut of beef.
There are a lot of good recipes for various types of beef roasts on the Food Network website.
Hope this helps!