Salisbury Steak

Salisbury steak for 1 with no sauce. It's really a big meat ball or a small meat loaf.

6&1/2 oz. ground beef,
2.5 oz. onion for mix,
2 T. beaten egg ( the rest for your dog),
2 T. panco or regular bread crumbs with 3 T. milk, stock or water,
1 T. tomato paste,
2 T. chopped flat leaf parsley ( don't forget to add it as I did),
1/4 tsp. salt and pepper,
3&1/2 oz. onion with 3 oz. mushroom( any kind),
I set my oven at 350 degrees convection roast for 35 minutes.