has become a generic term for just about any pot in the 5-7 quart range that is 8-10 inches in diameter, has a tight fitting lid, and the height of the sides are about 1/2 the diameter of the pot. A soup or stock pot will have sides taller than the radius - a casserole will have shorter sides.
If you're going to do all the cooking on the stove top - any heavy bottomed pot will work (anodized aluminum, stainless steel with an "encapsulated aluminum disk" on the bottom, etc.) These can also be used for other things, like boiling pasta, etc. They will also work in the oven - the max temperature range will depend on the cookware and lid materials.
Cast iron works well on the stove top (unless you have a ceramic stove top that says not to use it because it will be too heavy or scratch it) and is better in the oven than probably anything else. Cast iron absorbs and releases heat very slowly (it's poor conduction is what makes it great in this instance) ... as the oven cycles off and on - the cast iron maintains a much more uniform cooking temperature within the pot. That's also why it is the choice every grandmother (born before 1950) for frying. The weight and slow heating might not make it ideal for boiling pasta - but it's great for pot roasts, soups, stews, chili, frying, etc.
I grew up with a 5-qt cast iron dutch oven - like this
. You can find them just about anywhere (Target, WalMart, etc.) but the best prices I have seen have been at hardware stores. If you have an Ace Hardware store in your area you might want to check them out. Have you ever noticed that when Alton Brown is shopping for cast iron he goes to an Ace Hardware store? Just an observation.
Yes, it is cast iron and has to be treated and cared for as such. The alternative is porcelain/enamel coated cast iron, like that from Le Creuset, which also needs to be treated kindly to prevent thermal shock or impact chipping. If you screw up the seasoning on a cast iron pot you can redo it - screw up the enamel lining in Le Creuset you have to toss it. Hum ... Lodge (5-qt) cast iron pot form Ace is about $35 - a similar sized pot (5.5-qt) from Le Creuset is about $190.
Now, regarding slow-cookers vs cast iron (Lodge or Le Creuset) dutch ovens ... I can't think of a thing I can do in a similar sized slow-cooker that I can't do in a dutch oven, but I can think of things I can do in a dutch oven that I can't do in a slow-cooker.
RECIPES: Yep, that "Pot Roast with Roasted Vegetables" recipe looks totally yummy. Of course FoodTV has some easier pot roast recipes, too. I did a quick search of their pot roast recipes
and found 44. I Googled "pot roast recipe" and found a bunch more
to choose from.