01 - Preheat a grill or grill pan over medium-high heat.
02 - Brush chicken breasts lightly with 1 tablespoon olive oil and season with salt and pepper.
03 - Grill chicken for 5–6 minutes per side, or until fully cooked (internal temperature 165°F). Transfer to a plate to rest for 5 minutes, then slice thinly.
04 - While the chicken grills, brush nectarine wedges with a touch of olive oil. Grill for 1–2 minutes per side until charred and just softened. Remove and set aside.
05 - In a large bowl, whisk together remaining olive oil, balsamic vinegar, honey, Dijon mustard, minced garlic, salt, and pepper to make the dressing.
06 - Add spinach, red onion, cherry tomatoes (if using), and half the almonds to the bowl. Toss gently with the dressing.
07 - Divide the spinach mixture among plates. Top each with sliced grilled chicken, grilled nectarines, crumbled feta, and the remaining toasted almonds.
08 - Serve immediately.