Place a large plate, upside down, on top of the rolls in the pot. Fill a metal bowl with water and place this on top of the plate. You have to do this so that the rolls will stay put in the pan and not flow around when you add the cooking liquid.
Pour 2 ½ liter/ 10.5 cups boiling water into a jug. Grate the remaining bulb of garlic and add the garlic to the jug. Add the remaining lemon juice, the remaining tomato paste, the remaining tablespoon molasses, and the remaining salt (2-3 teaspoons to taste). Mix well and taste, it should taste salty and lemony.
Carefully add about ¾ of this mixture to the pot with the grape leaves. Pour the HOT liquid slowly into the pot around the edges of the upside plate in the pot.
Turn the heat on high and bring it to a boil.
Reduce heat to medium and cook for 1 hour.
Reduce the heat to low and cook for another ½ hour.
Take one roll out of the pan and check to see if the rice is tender. It should be really soft and a bit sticky.
If it's not done, add some more of the reserved cooking liquid and continue cooking on low, checking from time to time, until the rice is soft, about 20-30 minutes more.
Use as much of the remaining liquid as needed to keep the rolls stewing in it, but you don't have to use it all.
Serve hot with the chicken legs and yogurt or at room temperature with yogurt.