Crockpot Creamy Meat Balls

1/4 Cup butter
1 onion, chopped
2 lb ground beef
2 eggs
2 tsp salt
1/2 tsp pepper
1/4 tsp pepper
1/4 tsp marjoram
2-1/2 Tbsp flour
5-1/2 Tbsp tomato paste
3/4 Cup beef stock
4 tsp Worcestershire sauce
2 tsp vinegar
1/2 lb. mushrooms sliced
1 Cup sour cream

Saute onion in half butter until golden brown. Put onions in crock pot.

Mix together beef, eggs, salt and pepper. Form in small balls and brown. Sprinkle on tarragon, marjoram and flour.

Shake frying pan to turn meat balls and coat them with flour. Put in crock pot. Mix together tomato paste, beef stock, worcestershire sauce and vinegar in frying pan. Scrape bottom of pan and cook for 2 min. Pour over meat balls.

Cover crock pot. Cook on low about 1-1/2 hours. Melt remaining butter. Saute mushrooms for 5 minutes.