This is a really easy one and my family loves it!
1lb ground beef
1/4 c. chopped onion
salt & pepper to taste
1 can tomato soup
1 can green beans, drained
mashed potatoes

Cook ground beef and onion in skillet until beef is no longer pink and until onions are cooked. Drain fat. Season with salt and pepper. Mix in soup and beans. Put in casserole dish, cover with masked potatoes. sprinkle some paprika on top if you wish. Bake until hot about 35 minutes at 350 degrees.