Mix all ingredients except cilantro in medium bowl. Season with salt and pepper. Let stand at room temperature 1 hour. Stir in cilantro.
Sprinkle chicken with salt and pepper. Place flour in wide shallow bowl. Dredge chicken in flour, shaking off excess. Place on baking sheet.
Melt 1 tablespoon butter with 1 tablespoon oil in heavy large skillet over high heat. Add 3 chicken breast pieces to skillet and cook until brown and cooked through, about 3 minutes per side. Transfer to plate. Add remaining 1 tablespoon butter and 1 tablespoon oil to skillet and cook remaining chicken. Transfer to plate; tent chicken with foil to keep warm. Add broth to skillet and bring to boil, scraping up browned bits. Stir in pear nectar, mustard, and lemon juice. Boil until thick enough to coat spoon, about 4 minutes. Season to taste with salt and pepper. Place 1 chicken breast piece on each plate. Spoon sauce over. Divide salsa among plates.