In a large bowl, combine 2 tablespoons of the olive oil and 2 tablespoons of vinegar. Add the chicken, stir to coat and let stand for 10 minutes, turning occasionally.
Heat a grill or grill pan to medium-high heat. Remove chicken from the marinade and discard the marinade. Sprinkle the chicken with ¼ teaspoon salt and ¼ teaspoon black pepper.
Brush the grill grates with grapeseed oil. Place the chicken on the grill and grill for 6 to 7 minutes per side or until the internal temperature reads 165 F on an instant-read thermometer.
Slice the chicken against the grain into ½-inch-thick pieces.
In a large bowl, whisk together the remaining 1 tablespoon olive oil, 1 tablespoon vinegar, honey, and the remaining ¼ teaspoons each of salt and pepper.
Add the strawberries, blueberries and red onion and toss to coat. Add the arugula and gently toss to combine.
Transfer the salad to a large serving platter, top with the chicken and sprinkle the feta on top. Serve immediately.
Recipe source: My Recipes