Heat a large nonstick skillet over medium-high heat. Add 2 teaspoons olive oil to pan; swirl to coat. Add onion, thyme, and garlic to pan; sauté 8 minutes, stirring frequently. Add balsamic vinegar and 1/4 teaspoon salt. Cover, reduce heat, and cook 15 minutes or until onion is very tender, stirring occasionally. Remove from heat; stir in chives, butter, and lemon juice. Heat a large skillet over medium-high heat. Add 1 tablespoon olive oil; swirl. Sprinkle chicken with 1/4 teaspoon salt and pepper. Add chicken to pan; sauté 6 minutes on each side or until done. Serve with jam.