Heat oil in a large oven-proof skillet over medium heat, add the chicken and season with salt and pepper. Brown about 3 – 5 minutes per side. Set aside.
In the same skillet add the onion and garlic and sauté until the onions are tender and lightly browned, about 3 – 5 minutes.
Slowly add the thyme and arrowroot and cook for 1 minute.
Add the broth and scrape the brown bits off of the bottom of the pan with a spoon while the broth is sizzling when added. This deglazes your pan.
Add the chicken back to the skillet. Cover skillet and roast in the oven for 15 minutes or turn the heat down to medium-low and simmer on the stovetop for 15 minutes.
Remove from heat and serve with a salad, veggie or side dish of your choice.