Preheat your oven to 400°F (200°C).
In a large oven-safe skillet, heat olive oil over medium-high heat.
Add the chicken thighs, skin-side down, and sear for about 4-5 minutes until golden brown.
Flip the chicken thighs and add the sliced apple sausage, Brussels sprouts, onion, and garlic.
Sprinkle thyme, salt, and pepper over the dish and toss the vegetables to coat them evenly.
Transfer the skillet to the preheated oven and roast for 25-30 minutes or until the chicken is cooked through.
Remove from oven and let rest for a few minutes before serving.
Plate the chicken, sausage, and vegetables, and enjoy!