01 - In a small bowl, whisk together 2 tablespoons olive oil, lemon juice, minced garlic, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Coat the chicken breasts evenly with the marinade and let rest for 10 minutes at room temperature.
02 - Preheat an outdoor grill or grill pan over medium-high heat until hot and lightly smoking.
03 - Brush the peach halves lightly with olive oil. Place the chicken on the grill and cook for 5 to 7 minutes per side, until fully cooked through and juices run clear. Grill the peaches cut-side down for 2 to 3 minutes until distinct grill marks form and the fruit softens slightly. Remove everything from the grill.
04 - Allow the chicken to rest for 5 minutes, then slice thinly against the grain. Cut each grilled peach half into wedges.
05 - In a blender or food processor, combine the basil, mint, extra-virgin olive oil, white wine vinegar, honey, salt, and pepper. Blend until smooth and emulsified.
06 - In a large bowl, combine the baby spinach, sliced red onion, grilled chicken, peach wedges, crumbled feta, and toasted nuts. Drizzle with the basil mint vinaigrette and toss gently to coat all ingredients evenly.
07 - Divide among plates and serve immediately. Garnish with additional fresh basil or mint leaves if desired.