Lightly coat chicken with kosher salt and pepper.

Heat olive oil in large skillet over medium-high heat. Add chicken, skin side down, and cook until golden, about 6-8 minutes. Flip over and cook other side until golden. Remove chicken from pan and set aside.

Carefully pour out and discard 2/3 of the remaining oil and chicken drippings from the pan. Add onion, garlic and mushrooms to the same pan and cook over medium heat until the onion is tender, about 6-8 minutes. Add tomatoes and their juices, capers, chicken broth, and oregano and stir to combine. Season to taste with additional salt or pepper if needed.

Return the chicken to the pan. Bring to a simmer and simmer, uncovered, over medium-low heat for 20-25 minutes or until chicken is cooked through.

Once chicken is cooked, remove and heat sauce on high to thicken for 5-10 minutes, if necessary. If very liquidy, boil until it reduces to desired amount.

Garnish with julienned basil and serve.