1) Heat the butter and fry the onions until they are transparent.
2) Stir in the flour and cook until flour is golden brown. Make sure no lumps form.
3) Add crushed mint leaves, salt, pepper, and walnuts. Fry for a few minutes.
4) Add 5 cups of water and sugar to taste. Bring to a boil and simmer for 10 minutes.
Note: Serving Size: 4, Preparation Time: 40 Minutes, Degree of Difficulty: Easy