Carefully remove the grape leaves from the jar. Working in groups of 7 to 8 leaves, align the stems and cut them all at once with kitchen scissors. Repeat until you run out of leaves.
Place leaves in a colander placed in a large bowl. Pour hot tap water over them and soak for 1 to 2 minutes to remove the salt. Rinse once (*1) and then set it aside to drain thoroughly.
Pick out 5-6 larger or torn leaves for lining the pot. Set them aside.
Place the rice in a colander and rinse it under hot tap water until the water runs clear, for about 1 minute. Drain well.
To make the filling, in a large bowl, combine ground beef, rice, onion, tomato paste, dill, parsley, salt, pepper, and allspice if using. Mix well with clean hands until thoroughly combined. (*2)
Brush the bottom of a 5½ quart Dutch oven (or any other large pot with a lid) with olive oil. Line the bottom of the pot with the reserved (large and torn) grape leaves, fully covering the bottom.
To stuff the grape leaves: Lay one grape leaf shiny side down on a cutting board. Place 1 to 1½ teaspoons of filling in the center, near the stem end, and shape it into a 1½- to 2-inch cylinder. Fold the sides over the filling and roll from bottom to top. The finished roll should be approximately 2½ inches long. Place seam side down in the pot.
Repeat with remaining leaves, arranging rolls in a tight spiral pattern. You should have about 30 to 35 of them per layer. I had 2 full layers.
Place an inverted plate on top of the dolmas.
In a measuring cup, whisk together the boiling water, tomato paste, olive oil, and salt. Pour the liquid over the dolmas; it should come up around the sides of the rolls without fully covering the top layer.
Cover with a lid and cook over medium heat. It should come to a boil in 5-6 minutes. Once boiling, reduce the heat to medium-low and cook for 30 minutes.
Carefully remove the plate, add the lemon juice, cover it with the lid, and cook on medium-low heat for another 30 minutes*3. Be sure to keep a close eye on it so there is some liquid in the pot to prevent sticking. To check doneness, cut one dolma in half and check if the rice and meat are fully cooked.
Turn the heat off and rest covered for 20 minutes. This rest will help any leftover water be absorbed by the dolmas.
Serve warm with lemon wedges and garlic yogurt sauce, tzatziki, or yogurt dill sauce. Finish with a pinch of sumac if desired.