01 - Set your outdoor grill to medium-high heat, or place a grill pan over medium-high on the stovetop. Allow it to get thoroughly hot before adding anything.
02 - Pat the chicken breasts dry with paper towels. Drizzle both the chicken and asparagus with olive oil, then season evenly with kosher salt and freshly ground black pepper on all sides.
03 - Place the chicken breasts on the hot grill. Cook for 6 to 7 minutes per side until the internal temperature registers 165°F and the juices run clear.
04 - During the last 4 to 5 minutes of the chicken's cook time, lay the asparagus directly on the grill grates. Turn occasionally until crisp-tender with pronounced char marks.
05 - While the chicken and asparagus grill, combine the finely chopped Calabrian chili peppers with their oil, olive oil, minced garlic, fresh lemon juice, honey, and chopped parsley in a small bowl. Stir well and adjust seasoning with salt and pepper to taste.
06 - Transfer the grilled chicken to a cutting board and let it rest for 2 to 3 minutes so the juices redistribute. Slice diagonally if desired.
07 - Arrange the sliced chicken and grilled asparagus on serving plates. Drizzle generously with the Calabrian chili sauce. Finish with lemon zest and an extra sprinkle of fresh parsley.