Bring a large pot of water to a gentle simmer. Remove the core from the cabbage and carefully peel off large, intact leaves, blanching them in the hot water for 1-2 minutes until they become soft and pliable. Drain and set aside.
In a mixing bowl, combine cooked lentils, finely chopped onion, minced garlic, smoked paprika, chopped dill and parsley, and a splash of olive oil. Mix well until everything is evenly incorporated, and taste to adjust seasoning if needed.
Lay a cabbage leaf flat on your work surface. Spoon about 2-3 tablespoons of the lentil filling near the stem end of the leaf. Fold in the sides, then roll tightly from bottom to top, tucking in the filling as you go. Repeat with remaining leaves and filling.
Pour a layer of tomato sauce into the bottom of a baking dish. Arrange the cabbage rolls seam-side down in the dish, fitting them snugly together.
Pour the vegetable broth evenly over the assembled rolls, then cover the dish with a lid or foil to trap steam and keep everything moist.
Bake the rolls in a preheated oven at 180°C (350°F) for 35-40 minutes, until the sauce is bubbling and the cabbage leaves are tender. Check occasionally and add a splash more broth if the liquid reduces too much.
Remove the dish from the oven and let it rest, covered, for 10 minutes. This helps the flavors meld and makes the rolls easier to serve.
Garnish with extra chopped herbs or a squeeze of lemon if desired, then serve warm, enjoying the tender cabbage and flavorful filling with plenty of sauce.
