Heat oil in a large skillet over medium-high heat. Sprinkle chicken with 1/4 teaspoon salt, rosemary, and pepper. Add chicken to pan; cook 3 minutes on each side or until done. Remove from pan. Add fennel bulb to pan; sauté 1 minute. Stir in wine. Add 1/4 teaspoon salt, broth, raisins, and vinegar; cover and cook 4 minutes or until fennel is tender. Return chicken to pan. Sprinkle with nuts and fennel fronds.