With enameled cast-iron, I don't bother to heat the pot before adding the oil. For something that's open-pored, like plain cast-iron or carbon steel (like an old-school crepe pan), it's better to preheat the pan. I can't see any chemical advantage to preheating enameled, as it's inert and non-porous. Of course everything DOES need to be properly hot before you add the meat.
I can take or leave letting my roast get to room temp when doing a braise. It's going to be in the oven/pot long enough that it's going to be cooked to 200+ degrees all the way through no matter what. The only possible advantage of letting it warm up on the counter is that it will take marginally less time to cook. And by marginally, I mean you probably won't even notice, on the scale of pot roast cooking time. For a steak or a rib roast where you want the middle warm without the outside being totally dry and charred, room temp helps a lot.
The only real tip I can give on pot roast is to use the right cut of meat. You want something from the shoulder, which usually means chuck. It has an excellent mix of rich meaty flavor, collagen/connective tissue (which makes that gelatin thats critical to the silky mouthfeel of pot roast and BBQ), and fat. You can also use something from the leg (shank) or tail, which also have loads of connective tissue, but they're usually a little low on actual meat. If you get the right cut of meat and cook it low and long enough to get that collagen rendered, it's pretty hard to mess up the rest of it.
Why stove top and why oven?
The stove top provides high heat for searing, which generates browning (the famous maillard reaction) which creates delicious, savory flavor components.
The oven provides an even, gentle heat for longer cooking without burning.
The beauty of the braise
Braising is a technique where a food, usually a meat, is cooked slowly in a moist environment, partially covered with water. It is an ideal technique for tougher, generally less expensive meats, because it converts collagen to gelatin, changing the meat from tough to meltingly tender and wonderful.
Braising is more common than you might think. Chili con carne, and pot roast, osso bucco and coque au vin are all braised recipes.
Searing and braising
Many braising recipes start with a sear, which is most commonly done stove top, because of the high intense heat that is easy to generate. Alternate methods would be to use a broiler or an outdoor grill, but these are often not as convenient. The purpose is to generate the savory flavors (not as the old kitchen myth said, "to seal in juices").
Then the dish is finished in its liquid (which will later usually become the sauce) at a much more gentle cooking pace.
Braising is flexible
You can braise in the oven. The advantage is the heat is very even and predictable, and you can just let the pot sit in the oven for 2, 3, or even 4 hours without worrying about burning or sticking.
You can braise on the stove top, with a gentle flame (or lower electric element setting). You simply adjust to leave the pot contents at a slow simmer (bubbles form lazily, not continuously). There is slighty more risk of burning, and the occassional stir might not hurt, but especially with a good pan, no risk.
So almost any braising recipe can be easily converted to be stovetop only, by simply... erm... using the stove top for the long braising time. I prefer the oven personally, but that is a matter of convenience and easy control.
Quality cookware
Quality cookware like good multi-ply stainless steel, or your now famous dutch oven (from your previous questions) is ideal for braising because it can be used for both the sear (just like a cast iron pan) and for the slow braising portion. No need to dirty two pots or pans.
Recipes that are just stovetop
There are a countless myriad recipes that you can cook in your cast iron just on the stove top.
Anything:
- Fried
- Deep fried
- Boiled
- Braised
The one thing you may choose to avoid doing is highly acidic recipes, like tomato sauce, which are not great for your seasoning. On the other hand, in rotation with other recipes that rebuild the seasoning, or just doing some direct seasoning, there is no true harm done either.
Recipes that are just the oven
There are many recipes that would only be done in the oven.
Many braises skip the searing part. Even recipes that call for it can be done without, at some loss of flavor.
Any recipe you see for a crockpot can be done in a dutch oven in the regular oven.
Best Answer
You don't need to convert, because you can't overcook it.
Very briefly, because it has been discussed in many other places: there are types of meat which can be overcooked and types which can't. All recipes for crockpots are made from the type of meat which can't be overcooked. So you don't have to worry about cooking it too long. You just cook it for as many hours as you have time to wait for it. If you want to, you can leave it in for the same time as in the crock pot.
As for the temperature, you choose one which will allow for a slight simmer. It will be different depending on your oven (they are never accurate) and the amount and shape of the thermal mass inside (dutch oven + food). The first time, set it rather high (maybe try the 325 you saw in recommendations), and check on it every 20-30 minutes. Once it has reached 80 Celsius internal or above (or look for a slight simmer if you don't have a thermometer), turn the heat down by 50 F. Continue until simmer has stopped, then go back up 50 F. Next time set this temp from the beginning. You might want to heat the stew quickly on the stove first, then put it in the oven at the optimum temperature, else it will take ages just warming up in the oven.