In a large mixing bowl, combine the ground beef or lamb, uncooked rice, finely chopped onion, minced garlic, chopped parsley, dill, and mint (if using).
Add ground black pepper, salt, ground paprika, and ground cumin.
Drizzle in the olive oil and mix everything thoroughly until well combined.
If using fresh grape leaves, blanch them in boiling water for a few minutes until soft. For brined leaves, rinse them thoroughly and soak in hot water to remove excess salt.
Lay a grape leaf flat on a clean surface with the shiny side down and the stem end facing you.
Place about 1 tablespoon of the filling at the stem end of the leaf.
Fold the sides of the leaf over the filling, then roll it up tightly from the stem end to the tip, forming a small cylinder.
Repeat the process with the remaining grape leaves and filling.
In a large pot, drizzle a bit of olive oil on the bottom.
Arrange a few grape leaves in a single layer to cover the bottom of the pot (this will prevent the stuffed leaves from sticking).
Place the rolled grape leaves in the pot, packing them tightly in layers.
Drizzle the japrak with a little olive oil and top with lemon slices.
Pour the hot water and lemon juice over the japrak. The liquid should almost cover the japrak; add more water if needed.
Place a heatproof plate on top of the japrak to keep them submerged during cooking.
Bring the pot to a gentle simmer over medium heat.
Reduce the heat to low, cover, and simmer for about 45-60 minutes, or until the rice and meat are cooked through and the grape leaves are tender.
Remove the japrak from the pot and let them cool slightly.
Enjoy your meal!