In a sealable container, combine the boneless chicken breasts with olive oil, lemon juice, red wine vinegar, Greek seasoning, and sea salt. Seal tightly and shake gently to coat evenly. Marinate in the refrigerator for at least 30 minutes, or up to overnight.

In a mixing bowl, combine Greek yogurt, grated cucumber, minced garlic, lemon zest, lemon juice, fresh dill, sea salt, and black pepper. Mix until smooth and well incorporated. Cover and refrigerate until serving.

Heat a cast-iron skillet over medium-high heat. Add the marinated chicken and cook for 3-4 minutes on each side until golden brown and reaching an internal temperature of 165°F (74°C). Remove from the skillet and let it rest.

In a small bowl, whisk together olive oil, red wine vinegar, dried oregano, and a pinch of sea salt. Set aside.

Begin assembling your bowls by dividing the cooked chicken into portions. Add diced cucumber, halved cherry tomatoes, sliced red onion, Kalamata olives, and crumbled feta cheese on top. Drizzle with the dressing and add a dollop of tzatziki before serving.