Remove stems from grape leaves and any torn leaves. (Most leaves can be cut in half - smaller ones remain whole.)
Mix herbs, spices, tomato, onion, lamb, olive oil, salt and pepper into rice. Mix well by hand until well combined.
Grease the bottom of the pot and put foil in the bottom. Line the bottom of the pot with any discarded grape leaf pieces. Top with tomato slices.
Lay out a single grape leaf. Place a small amount of filling in the centre. Fold over edges and the roll up grape leaf longways.
Roll tightly so they don’t come apart but not so tight that they tear.
Place the rolled grape leaves tightly against each other in layers. Place a plate that is heatproof and slightly smaller than the pot on top of the grape leaves to keep in place during the boiling process.
Mix the tomato puree into the broth until dissolved. Pour the broth mixture over the grape leaves keeping the plate in place. Bring to a boil.
Turn down to a simmer and cook like you would rice. Once the water has evaporated below the top layer of grape leaves, remove the plate.
Cooks for about an hour and a half until all the liquid has evaporated.
Remove from the heat and allow to rest in the pot for ten minutes.
Remove the lid and place the serving plate over the pot. Flip pot so grape leaves are transferred to the plate.
Let the contents settle for a couple of minutes before removing the pot. Serve with yogurt.