Place a chicken breast inside a Ziploc bag. On a cutting surface, pound breast with mallet to 1/3 inch thickness. Repeat with remaining breasts. In a shallow bowl, place flour, thyme, salt and pepper and lemon zest. Flour each breast. Remove excess flour. Melt butter in large saucepan over medium heat. Add olive oil. Sauté each chicken breast for 7 minutes, turning once, or until golden brown. Remove. Drain on paper towels. Cook pasta until done. In saucepan used for chicken, add wine and bring to boil. Scrape off bottom of pan. Add chicken back to pan. Add broth, capers and parsley. Sauté for 7 minutes until chicken is done. Add sour cream and juice of the lemons and mix thoroughly. Heat though. Garnish with chopped fresh parsley. Serve chicken over pasta with sauce.