Preheat oven to 375°F.
In an oven-safe pan, add 2 tablespoons of avocado oil. Season both sides of all chicken thighs with salt.
Place chicken thighs skin side down into oil and cook for 5 minutes. Turn chicken & cook for an additional 1 minute. Remove from pan & set aside.
In the same pan, add onions & garlic. Cook for 3 minutes until translucent.
Add remaining oil, tomatoes, and olives & mix to combine. Cook for 5 minutes, then add salt, thyme, and sugar & cook for an additional 2 minutes.
Place the chicken thighs back into the pan, spoon the liquid over the chicken and sprinkle with salt & pepper to taste.
Cover with an oven-safe lid & bake for 20 minutes. Remove and baste again with tomato liquid and bake at 425°F for an additional 20 minutes.
To serve, plate with your favorite sides & garnish with fresh parsley.