Heat a large skillet over medium-high heat and add olive oil. Add shallots and garlic and sauté over medium-low heat for 4-5 minutes, or until golden. Add butternut squash, cranberries, maple syrup and 1 tablespoon water and cover; cook on low for 10 minutes.
Remove lid and add kale, salt, sage, and pepper, cover and cook for another 3-4 minutes. Set aside to cool and mix in pecans.
Cut a pocket into the sides of the tenderloins, careful not to cut all the way through at the ends. Season the inside and outside of the turkey with salt.
Stuff each turkey breast with about 3/4 cup of squash mixture. Cut cooking twine long enough to tie each breast with 3 to 4 pieces of twine. Cut off extra twine.
Preheat oven to 375°F.
Heat an oven-safe skillet over medium-high heat, lightly spray with cooking spray. Carefully sear each turkey breast on each side about 2 minutes. Pour 1 tablespoon water into the skillet and cover tight with foil. (Or transfer to a baking dish and cover tight with foil). Cook in the center of the oven 25 minutes.
Allow to sit 5 minutes before cutting off twine and slicing each turkey breast in 4 slices. Spoon any pan juices over the turkey and serve.