1/4 c. butter
3 c. thinly sliced onions
1 1/2 tsp. salt
2 tbsp. flour
4 c. beef broth (bouillon cubes will do - make ahead)

Combine in pot with lid butter and onions. Cover and cook slowly about 15 minutes. Blend in salt and flour. Add beef broth. Heat to boiling. Reduce heat and simmer about 1 hour.