Preheat the oven to 425.
Toss the chicken in 2 Tablespoons oil, 1 Tablespoon balsamic, garlic, S&P, and 1 teaspoon dried thyme.
In an oven safe pan, add 1 Tablespoon oil and 1 Tablespoon butter. Add the onions and season with salt and pepper. Once golden (15 minutes), remove the heat and add the 1 teaspoon thyme and 1 Tablespoon balsamic. Toss and remove.
Add more oil and the chicken thighs. Sear each side for about 2 minutes and remove (they will cook through in the oven).
Add the rice and cook for 3 minutes. Then add the broth, cream, more S&P, and bring to a simmer.
Add the onions and chicken back and then cover in foil and bake for 20-25 minutes.
