Boil the Cabbage Leaves: Remove the core of the cabbage and gently separate the leaves. Bring a large pot of water to a boil, then blanch the cabbage leaves in batches for 1–2 minutes, until softened. Set aside to cool.
Mix the Filling: In a large bowl, combine rice, onion, garlic, tomatoes, tomato paste, parsley, dill, dried mint, black pepper, paprika, salt, sumac, lemon juice, and olive oil. Mix well to evenly distribute the flavors.
Stuff the Cabbage Leaves: Lay a cabbage leaf flat, trimming the thick stem if necessary. Place a spoonful of the filling near the base, fold in the sides, and roll tightly like a burrito. Repeat with the remaining leaves and filling.
Layer the Rolls in a Pot: Line the bottom of a large pot with any leftover cabbage leaves to prevent sticking. Arrange the stuffed rolls tightly in layers.
Make the Sauce: In a small bowl, mix olive oil, tomato paste, paprika, mashed garlic, dried mint, and hot water.
Simmer: Place a plate or small lid on top of the rolls to keep them from unraveling during cooking. Cover the pot and cook over low heat for 45–60 minutes, until the rice is fully cooked and the flavors are well combined.
Serve Warm: Serve the Lahana Sarma warm, drizzled with extra sauce. Pair with yogurt or a squeeze of lemon for added brightness.