Combine meat with rice, butter, salt, pepper and set aside.
If using fresh grape leaves, rinse well and place in pan of hot water. Turn off heat and allow leaves to soften for 10 minutes. Squeeze out excess moisture.
Use medium sized tender leaves. If small, use 2, overlapping a little. Place a rounded teaspoon of filling at the stem end of leaf. Spread out to form a line. Tuck in the sides and roll away from you, forming a thin tube.
Put a few slices of raw potato in the bottom of a saucepan along with a slice of lemon and the garlic cloves. Arrange the rolled leaves in the pot alternating the direction of each row. Sprinkle with salt and lemon juice and weigh down with plate and saucer of water. Add enough water to cover the plate. Bring to a boil, lower heat and simmer for 30-40 minutes.