In small bowl, combine agave with juice concentrate, orange zest, garlic, salt and red pepper flakes. Rinse chicken with cold water and pat dry. Season lightly with salt. In large non-stick skillet, heat margarine and oil over medium-high heat. Add chicken and cook about 4 minutes, until seared. Turn chicken; cook another 4 minutes until just cooked through. Pour agave mixture over chicken and cook, turning chicken to coat as sauce begins to thicken, about 2 minutes. Serve chicken breasts with agave-orange glaze spooned over the top.