Preheat the oven to 400°F.
Slice the very tops and bottoms off each squash to form a flat surface, then cut them in half width-wise. Scoop out the seeds and coat the inside and outside of the squash with olive oil, salt, and pepper.
Place the squash cut side up on a lined baking sheet. Roast for 40-45 minutes until tender and they can be pierced easily with a knife.
Meanwhile, heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the ground chicken, sage, fennel seeds, garlic powder, nutmeg, red pepper, salt, and black pepper to the skillet. Cook until the chicken is no longer pink, about 6-7 minutes.
Add the onion and kale stems to the skillet and cook until tender, about 5 minutes.
Add the kale leaves and apples to the skillet. Pour in the chicken stock and sprinkle in the almond meal. Cook until the kale leaves are tender, about 5 minutes.
Remove the squash from the oven and stuff each half with the chicken mixture. Sprinkle some almond meal on top of each squash, then return to the oven and roast for another 15 minutes.