1. In a skillet, heat half the oil over medium-high heat. Cook the onion, thyme and apples (until apples are tender yet still crunchy). Set aside.
2. Heat the leftover oil and cook chicken 2-3 minutes per side. Add salt and pepper to taste.
3. Reduce heat to medium-low, deglaze with cider vinegar and add apple juice, setting aside 2 tbsp. Cover and simmer for 6 to 10 minutes until chicken is cooked to an internal temperature of 77° C (170° F). Remove chicken and keep warm.
4. Mix cornstarch with the rest of the juice. Add maple syrup to mixture and put in the skillet. Heat over high heat and let thicken. Warm the onion and apples. Glaze the chicken breasts with the apple mixture and serve.