Bring a large pot of water to a rolling boil and blanch the grape leaves for 3 minutes, to soften. Remove with a slotted spoon and transfer to a bowl filled with ice water.
Grate the tomatoes on the coarse side of a hand grater. Place the tomatoes, broad beans, bulgur, onions, scallions, garlic, and herbs in a mixing bowl and toss to combine. Add the cumin and season generously with salt and pepper. Mix in half the olive oil and a cup of water at room temperature. Let the mixture stand for 15 minutes.
Drain the grape leaves and place vein side up on a work surface. Using a kitchen scissors or small knife, snip off the stems. Place as many grape leaves as will fit in neat rows in front of you on a work surface. the leaves should be placed vein side up, with the pointy part at the top and the stem end at the bottom, nearest you. Place any torn or very small leaves on the bottom of a wide pot to cover the surface.
Take a heaping teaspoon at a time of the filling and place on the bottom center of the first leaf. Fold in the sides then roll up to form a small cylinder. Place seam side down inside the pot, along the outer rim. Continue filling and rolling until done. You can place the dolmades in multiple layers on top of one another, so long as in each layer the stuffed grape leaves are placed snuggly next to one another. Pour in remaining olive oil and enough water to cover the leaves by ¼ inch/55 cm.
Cut a piece of parchment to the circumference of the pot and place over the paper. Cover the pot and bring the grape leaves to a simmer over medium heat. Reduce to low and simmer for about 50 minutes to an hour, until tender.