1Cook linguine as directed on package. Meanwhile, sprinkle chicken with salt and pepper. In 12-inch nonstick skillet, heat 1 tablespoon of the butter over medium-high heat until melted.
2Cook chicken in butter 5 to 7 minutes, stirring occasionally. Add onions, garlic, roasted peppers and asparagus; cook 2 to 3 minutes longer, stirring occasionally, until asparagus is crisp-tender and chicken is no longer pink in center. Stir in broth and remaining 1 tablespoon butter; cook until butter is melted.
3Drain linguine. Serve chicken mixture over linguine. Sprinkle lemon peel over each serving.