Heh. Gladys' anger is as hot as the oven.
I don't know how long a roast is supposed to cook. The only roast I've cooked goes in the crock pot and I don't have to worry about it. But I don't think Brutus' statement implies Gladys is a bad cook. Maybe Brutus should've asked how much longer it'll take to cook or how long has it been in? Then Gladys could've answered with "About thirty more minutes in the oven and then thirty minutes in your ass if you don't get out of my kitchen."