Squeeze the chopped onions with your hands to make them soft, add all the rest of the ingredients and mix well. This mixture is the filling. If the leaves are freshly picked, soak them in boiling water for a few minutes. If they are canned, then wash them in hot water. Cut off the stems. Spread a leaf on a small plate, wrong side up and stem end towards you. Put a teaspoon full of the filling near the stem end, with your hands fold over the sides, then start rolling from the stem up like a cigarette. Place some leaves in the bottom of the pan to prevent the Sarma from burning and arrange the rolled leaves side by side in the pan and in two or three layers according to the size of the pan. Place a plate over the to to keep them in place, add two cups of water, cover and cook on slow fire for one and a half hours, or better, cook in medium oven for the same length of time. After they are cooked, do not remove plate until Sarmas have cooled to prevent discoloring. Serve cold, sprinkle with olive oil to make them shine. Garnish with lemon slices.