Brown ground beef and chopped onion 

Add and mix thoroughly
1 pkg Mc Cormick mushroom gravy mix
a little beef broth or bouillon with water
Oregano, garlic powder, black pepper, sherry wine.

Spread meat mixture in the bottom of a casserole dish.

Cover with 
Hot mashed potatoes with some small cheese chunks mixed in.

Topping
Bread crumbs and Parmesan cheese

Bake in 350 oven until hot through.

This is one of those recipes which you may adjust the amounts. Just add more ground beef and potatoes depending on how may you are serving. It is really great.