Bring a large pot of water to boil. Trim the cabbage base and blanch leaves for 3–5 minutes until slightly softened. Cool.
Mix all filling ingredients in a bowl until combined. Trim the thick vein from cabbage leaves. Place filling on each leaf and roll, keeping edges tucked to prevent spilling.
Arrange stuffed cabbages tightly in a wide ovenproof pot or baking dish, layering with cabbage leaves or tomato slices if desired. Mix sauce ingredients, taste, and adjust. Pour over rolls until covered, leaving a little extra liquid.
Cover with parchment, then a heatproof plate, then foil. Bake in a preheated oven at 200°C/390°F for 1 hour. Remove the cover and bake for another 30 minutes.
Finish with a drizzle of olive oil and fresh lemon juice before serving.