Heat olive oil over medium high heat. Meanwhile season chicken with salt and pepper, and additional olive oil if desired. When oil is heated add chicken thighs. You should hear a sizzle when you add them to the pan. Allow them to cook for 2 to 3 minutes undisturbed, turn them over when browned and skin is crisp. Cook for an additional 2 to 3 minutes until the other side is browned. Turn heat down to medium low and cover. Cook for 10 minutes, then flip the chicken and cook for an additional 10 minutes or until temperature reads around 140 degrees Fahrenheit. Remove chicken from skillet.

Increase heat to medium. Add butter and onions to the skillet with the pan juices from the chicken thighs. Deglaze the pan and cook until onions are just tender and transparent. Stir in the mushrooms and garlic.

Add remaining ingredients to the skillet and stir to combine. When adding the xanthan gum, make sure to add it slowly while stirring continuously to avoid clumping.

When sauce begins to thicken, gently replace chicken thighs and reduce heat to a simmer. Cover skillet and cook until chicken is 165 degrees Fahrenheit, approximately 10 minutes.

Remove thyme stems from the sauce. Serve chicken with mushroom cream sauce poured over the top. Garnish with additional fresh thyme if desired.