Marinate the chicken. Whisk the balsamic vinegar, olive oil, dijon mustard, minced garlic, salt, dried oregano and black pepper together in a large bowl. Then add your chicken thighs and let them marinate for at least 30 minutes – 4 hours.
Make the strawberry-feta topping. While the chicken marinates, mix the diced strawberries, crumbled feta cheese and sliced basil together in a bowl and season with salt and pepper to taste. Cover and keep it chilled in the refrigerator.
Grill the chicken. Preheat your grill to medium-high heat and oil the grates to prevent sticking. Once hot, remove the thighs from the marinade and place them directly on the grill. Cook for 5-6 minutes per side (or until they reach an internal temperature of 165 degrees).
Serve. Spoon your strawberry topping over each individual chicken thigh and drizzle your favorite balsamic glaze over the top.
