Prepare the cabbage leaves:
Bring a large pot of salted water to a gentle boil. Core the cabbage and carefully lower it into the pot. Simmer for 5–6 minutes until outer leaves begin to soften. Peel off 10–12 large leaves as they loosen, placing them on a towel to cool. Trim the thick rib at the base of each leaf so they fold easily.

Make the filling:
In a large skillet, heat olive oil over medium heat. Sauté onion for 4 minutes until translucent, then add garlic and cook until fragrant. Stir in cremini mushrooms and cook until golden, about 7–8 minutes. Add porcini mushrooms, lentils, brown rice, smoked paprika, thyme, salt, and pepper. Mix well and cook for another minute or two. Taste and adjust seasoning.

Prepare the tomato sauce:
In a saucepan, warm olive oil over medium heat. Add garlic and cook briefly, then stir in crushed tomatoes, sugar, herbs, salt, and pepper. Simmer uncovered for 10–15 minutes, until slightly thickened and flavorful.

Assemble the rolls:
Preheat oven to 375°F (190°C). Spread 1 cup of tomato sauce over the bottom of a large baking dish. Place a cabbage leaf flat on your surface, add ⅓ cup of filling, and roll tightly, folding in sides like a burrito. Place seam-side down in the baking dish. Repeat with remaining leaves and filling. Pour remaining sauce evenly over top and cover tightly with foil.

Bake:
Bake for 40–45 minutes until the rolls are tender and the sauce is bubbling. Let cool for 10 minutes before serving.

Serve:
Spoon extra sauce over the top, garnish with fresh herbs, and enjoy warm.