Rhubarb Sauce

Serve this Persian sauce, which has an unusual tart flavor, with plain rice steamed in the Persian manner or the quick and easy boiled and steamed rice.
- 4 tablespoons butter or vegetable oil
- 1 onion, finely chopped
- 1 pound lean stewing beef or lamb, cubed
- Salt and pepper
- ½ teaspoon cinnamon
- ¼ teaspoon allspice
- 1 pound fresh rhubarb stalks
- Juice of ½ lemon
- ½ cup chopped flat-leaf parsley
- ¼ cup chopped fresh mint
Instructions:
- Heat 2 tablespoons of the butter or oil in a large saucepan and fry the onion until golden. Add the meat and sauté, turning the pieces, until browned all over. Cover with water and add salt, pepper, cinnamon, and allspice. Bring to the boil and simmer for 1 ½ hours, until the meat is very tender, adding water to keep the meat covered.
- Trim the rhubarb stalks and cut them into 2-inch lengths. Sauté in the remaining butter or oil for a few minutes, then sprinkle with lemon juice and cook for a few minutes longer. Add to the meat sauce with the parsley and mint and simmer for 10 minutes.