In a medium bowl, pour in the basmati rice. Pour hot water over the rice to cover and allow to soak for 30 minutes to an hour. After that, pour the rice into a sieve and wash thoroughly until clean. Place the sieve over a bowl to drain.
Pour the grape leaves from the jar into a bowl of cold water. Reserve until ready to use.
Rinse and clean the parsley really well. Pat dry with a paper towel. Chop the Italian flat-leaf parsley and set aside. Slice the tomatoes into ½" slices and set aside. Slice the green onion and set aside. If you're using fresh mint, chiffonade and set aside. Peel and slice most of the carrots lengthwise and the rest into rounds and set aside. Peel and slice the potatoes into 1'2" slices and set aside. Dice the second set of tomatoes into a small dice and set aside. Now all your prep work is done.
Pour the rice into a large bowl. Add in the parsley, diced tomatoes, mint, green onion, black pepper, salt, seven spice, and olive oil. Mix gently until combined. Pour this mixture into a sieve and allow it to drain over a bowl. Keep this excess liquid as we'll be using it later to make a sauce.
While your filling is draining, place most of the carrots into the bottom of a large pot, reserving about ¼ of the carrots for later. Layer all the sliced potatoes on top of the carrot layer.
Take the grape leaves out of the cold water. When rolling the grape leaves, use scissors to cut the stem off the grape leaf. Lay the grape leaf flat on a baking sheet. Take about 1 to 1 ½ teaspoons of the filling mixture and mound it into a cylinder shape into the middle of the leaf. Bring the left and right side of the leaf into the middle and roll from the bottom to the top tightly, but not too tightly. If you did it correctly, it should look like a cigar. Continue to roll grape leaves until you run out of the filling.
Gently lay most of the rolled grape leaves over the potatoes, reserving ¼ of them for the second layer. Place the sliced tomatoes over the rolled grape leaves. After the sliced tomato layer, gently lay the rest of the grape leaves on top.
Take the excess liquid we drained off from the filling and in the same bowl, whisk in some olive oil, salt, black pepper, seven spice, lemon juice, and water. This is our sauce for the dish.
Place a plate bottom-side up so that the top of the plate is facing the grape leaves. Pour the sauce you made over the top of the plate, so the liquid runs down into the pot. Place the pot over high heat and weigh the plate down with a jar filled with water or measuring cup filled with water. Cook until it reaches a boil. Right when it reaches a boil, turn down the heat to medium-low and cook until the grape leaves are tender and the rice is fully cooked, for us, it takes about an hour and a half. Taste test at around the hour mark to see if you've finished cooking.
Serve hot, warm or cold. These grape leaves can be served at any temperature. You can make a sandwich by rolling them in Pita or you can just snack on them with a fork or your hands. Enjoy!