This is adapted from a recipe in a Taste of Home Christmas cookbook. I make this often for my family and it's a great company dish. I usually serve it with mashed potatoes but it's also good with pasta or rice.
In a skillet, brown pork in the butter after sprinkling on the salt and pepper. Transfer meat to a glass 9x13x2 ungreased cake pan. In the pan drippings, saute the onion and mushrooms until tender.
Combine flour and brother until smoth; add to skillet. Bing to a boil; stir and cook for 2 minutes adding a bit more chicken broth if needed. Pour over meat. Cover and bake at 325 degrees F for 1 hr or until a met thermometer reatds 160-170 degrees F. Let stand 5 minutes before slicing.