Pat chicken dry with paper towels and place on cutting board. Cut chicken in half horizontally to form thin cutlets. Season with salt and pepper on both sides.
Preheat grill pan, outdoor grill or skillet to medium-high heat.
Once pan is hot, coat with oil. Add chicken to pan and grill, turning once, until cooked through, 3-4 minutes per side.
Wash and dry spring mix. Place in medium bowl.
Wash and dry blueberries. Add to bowl with mixed greens. Using clean cutting board, roughly chop pecans. Add to bowl.
Transfer cooked chicken to cutting board and cut into thin strips.
In bowl, mix olive oil and balsamic vinegar to create dressing.
Add chicken and dressing to salad bowl; toss to combine.
To serve, divide salad between plates or bowls and crumble goat cheese over top.