Serbian sarma is similar to Greek dolmas, though its made with cabbage instead of grape leaves. The usual sarma is made with ground pork and chuck, resulting in a rather disgusting combination of meat, oil and cabbage. We take it down a notch for lent, during which most days are spent fasting on a vegan diet. Hence: lenten (posna) sarma. This recepie sounds a bit odd, so one could use grape leaves instead to Greek it up.
Cut out the hard core of the cabbage; or, if using sweet cabbage, boil it and then separate each leaf. Heat oil in a skillet, then add onions, celery and pepper. Fry until soft. Add cooked rice, stir and fry the whole deal. Remove from heat, add salt and walnuts, mix well. Scoop approximately a tablespoon onto cabbage leaf and roll that baby up. Place the rolls in a large pot, adding tomatoes and enough water to cover them up. Cook over a slow boil (medium heat) for about an hour. Keep covered until its time to eat.