Saut onion and 1/4 of the mushrooms in a bit of olive oil until onions are translucent and mushrooms have browned a bit, set aside to cool
Combine ground meat, cooled mushroom mixture, bread crumbs, eggs, and season with salt and pepper mix thoroughly
Lightly oil the bottom of a baking dish and form meat mixture into a loaf brush with ketchup
Bake in a 350deg oven for about 1 hour or until meat thermometer registers 135deg then remove from oven and rest for about 10 minutes before slicing
While meatloaf is in the oven melt butter in a heavy bottom sauce pan and saut mushrooms until most of the moisture has evaporated, sprinkle with flour to make a roux (use more flour and butter if you want a thicker gravy) and cook for a couple of minutes add beef broth and bring to a boil, then reduce to a simmer stirring until gravy thickens, adjust seasoning
