Preheat your oven to 400F. Then, add egg, coconut flour, grated apple, grated yellow onion, garlic, sage, thyme, salt & pepper to a large bowl. Whisk until combined. Add in the ground chicken and use your hands to gently incorporate, without over-mixing. Set aside.
Add sweet potato, brussels sprouts and chickpeas to an extra-large baking sheet (21 x 15"). If you don't own one this big, split it between two normal-sized baking sheets. Then, drizzle avocado oil and seasonings over the top. Toss to coat and then spread out evenly on the baking sheet(s). There should be minimal overlap.
Scoop out 2 tbsp of the ground chicken mixture and roll into a ball. Then, nestle the meatballs onto the baking sheet. It should make about 16-18 meatballs. Transfer to the oven and cook for 20 minutes. Optionally, switch your oven to broil for a few more minutes to get a nice golden finish on the meatballs and the veggies.
Meanwhile, add all maple tahini sauce ingredients to a small bowl and stir until combined and smooth. Continue to add more water as needed to get it to your desired consistency. It thickens up as it sits.
Drizzle the maple tahini sauce over the sheet pan. Top with chopped parsley, if you'd like. Enjoy!
