I've a grass-fed arm roast that is much too long to fit in my crock pot - so it will have to go in the oven. I've a glass dish it will fit in and aluminum foil will seal it nicely. I've not much experience with cooking red meat - many of the recipes I've seen appear to assume that this type of roast requires marinating for a couple of days Is that really necessary? I know that it needs slower cooking, pity it won't fit in my crock pot. Right now I can't do anything with it until it thaws - the meat I get from my grass-fed farmer are frozen HARD - it takes longer to thaw then frozen meat from the store for some reason.