01 - Preheat a grill or grill pan over medium-high heat. Season the chicken breasts generously on both sides with salt and freshly ground black pepper.
02 - Place the seasoned chicken on the grill and cook for 5 to 7 minutes per side, until the internal temperature reaches 165°F and juices run clear. Transfer to a plate and let rest for 5 minutes before slicing thinly against the grain.
03 - In a small bowl, whisk together the olive oil, balsamic vinegar, Dijon mustard, and honey until fully emulsified. Season with salt and pepper to taste. Set aside.
04 - In a large salad bowl, combine the mixed greens, sliced strawberries, red onion, avocado, and chopped pecans. Toss gently to distribute evenly.
05 - Arrange the sliced grilled chicken over the salad and scatter the crumbled goat cheese on top.
06 - Drizzle the balsamic vinaigrette over the salad just before serving. Toss lightly if desired, or serve with dressing on the side.