To stuff and roll the grape leaves, lay a grape leaf flat on a cutting board, scoop out a heaping teaspoon of the rice mixture into the center of the grape leaf, and carefully fold in the sides and roll it like you would when making a wrap. Repeat until all the stuffing has been used and place the wrapped grape leaves in a tray.
Line the bottom of a large pot with tomatoes and/or potatoes and season with salt and pepper. Neatly arrange the stuffed and rolled grape leaves in rows, alternating directions, to completely cover the circumference of the pot. Drizzle each layer with olive oil and season with salt and pepper to taste.
Place small round plate on top of grape leaves in the pot to hold them down and prevent floating while they are cooking.
Add 5-6 cups of boiling water to completely cover the grape leaves and the plate, then cover the pot and cook on Medium heat for 30 minutes, until most of the water is absorbed and the rice is cooked.
Add the lemon juice on top of the grape leaves, then cook on low heat for an additional 45 minutes.
Remove from heat and let cool uncovered for 30 minutes. Transfer to a dish and enjoy warm!