Heat 4 tablespoons butter in large skillet over medium heat. Add onion and cook 4 minutes, stirring occasionally. Add apples and kale and cook 3 to 4 minutes or until kale is wilted, stirring occasionally.

Meanwhile, place egg in large bowl and whisk until smooth. Add stuffing mix, stock, 1 teaspoon salt, 1/2 teaspoon pepper and onion mixture, stir until well combined.

Preheat oven to 325 degrees F. Place baking rack on rimmed sheet pan.

Lay turkey breast, skin side down, on work surface. Sprinkle turkey with remaining 2 teaspoons salt and 1 teaspoon pepper. Spread the stuffing mixture evenly over meat, leaving 1/2-inch border on all sides. Sprinkle cheese evenly over stuffing.

Starting at one short end, roll turkey like a jelly roll, tucking in any stuffing that may fall out on the sides. Using twine, firmly tie the roll every 2 to 3 inches to make a compact cylinder.

Place the roulade seam side down on prepared rack on sheet plan. Melt remaining 2 tablespoons butter and brush over roulade.

Transfer to oven and roast 2 hours or until center of roulade reaches 150 degrees F. Remove from oven and cover roulade with foil. Allow to rest at room temperature 15 minutes before slicing and serving.