Season both sides of chicken breasts with salt and pepper. Preheat oven to 350°.
Heat large oven safe skillet to medium and add olive oil. Sear chicken pieces on both sides just until lightly browned. Remove to a plate.
Rinse and chop onion, garlic and tomatoes. Reduce heat to medium low, add onion to pan and cook quickly until slightly softened. Add garlic and cook just until softened but not browned.
Turn heat back to medium and add white wine. Deglaze pan by scraping up all bits of colour from chicken and onion, incorporating into the wine. Allow wine to cook a few minutes to remove most of alcohol.
Add tomatoes, lemon juice, oregano and thyme.
Drain and chop olives and add to pan. Drain capers and add to pan.
Stir sauce, then add chicken pieces back into pan. Spoon sauce over each piece. Cover pan and roast in oven for about 20 minutes until chicken is cooked through but still juicy.
Serve with potatoes and spoon extra sauce over top.