Preheat oven to 400° F.
Line a large sheet pan with parchment paper. Place the sweet potatoes, yellow onions, carrots, apples, and sausages on the sheet pan. Pour over 2 tbsp avocado oil. Season with sea salt to taste. Massage with your hands to coat evenly. Spread out in a single layer and create spaces to place the chicken thighs.
Place the chicken thighs on a flat surface and pat dry. Distribute 1 tbsp avocado oil over the chicken thighs. Season with sea salt and pepper on both sides and rub in with your hands. Place on the sheet pan.
Bake at 400° F for 40 minutes, or until the chicken thighs reach an internal temperature of 165° F and the vegetables are fork tender to your liking. Plate, serve hot, and enjoy!