Begin by slicing the cabbage into thin, ¼-inch strips. Place the shredded cabbage in a large, heatproof bowl and pour boiling water over it. Let it sit for 10 minutes to soften the leaves. After soaking, drain the cabbage thoroughly and squeeze out any remaining moisture with your hands to prevent excess liquid in the mixture.
In a large mixing bowl, combine the ground turkey and ground pork with the cooled, cooked rice and the drained cabbage. Grate half of the onion directly into the meat mixture for extra moisture and flavor. Add the eggs, 1 teaspoon of Mrs. Dash, 2 teaspoons of salt, ½ teaspoon of black pepper, and the chopped parsley or dill. Mix everything together with your hands or a large spoon until fully incorporated, but avoid over-mixing to keep the texture tender.
Shape the mixture into oblong patties about the size of a small potato—roughly ½ cup of filling per roll. Place them side by side in the prepared casserole dish.
To prepare the sauce, finely dice the remaining half of the onion. In a large saucepan, heat the olive oil and butter over medium-high heat. Add the diced onion and sauté for about 5 minutes, stirring occasionally until the onion becomes translucent and soft. Stir in the grated carrot and cook for an additional 3 minutes until tender.
Next, pour in the marinara sauce and hot water, stirring to combine. Bring the mixture to a boil, then season with ¼ teaspoon salt and ¼ teaspoon of Mrs. Dash, or adjust seasoning to your taste.
Carefully pour the hot sauce over the arranged patties, making sure they are nearly submerged in liquid. Cover the dish tightly with foil and bake on the center rack of the oven for 40 minutes. The cabbage rolls should be fully cooked and tender, and the sauce slightly thickened.
To serve, plate the cabbage rolls and spoon some of the flavorful sauce over the top. They pair beautifully with a dollop of sour cream or plain Greek yogurt on the side.