In a large bowl, combine the Greek yogurt, lemon juice, 2 tablespoons extra virgin olive oil, red wine vinegar, garlic, oregano, paprika, cumin, coriander, optional cayenne, salt, and black pepper.
Add the chicken tenders and toss until every piece is thoroughly coated with the yogurt marinade. Cover and refrigerate for at least 30 minutes. For deeper flavor, you can marinate the chicken overnight.
Prepare your favorite homemade Greek dressing and set it aside while you assemble the vegetables.
Place the chopped romaine, tomatoes, bell pepper, cucumber, shallots, and Kalamata olives in a large salad bowl. Add about 4 tablespoons of Greek dressing and toss gently until everything is evenly coated.
Taste the salad and add additional dressing or salt as needed. Crumble or cube feta over the salad according to your preference. Reserve about 3 tablespoons of dressing for finishing the dish.
Heat about 1 tablespoon of extra virgin olive oil in a nonstick skillet over medium-high heat. Allow the excess marinade to drip from the chicken before placing the tenders in the hot skillet.
Cook the chicken without moving it for about 5 minutes, or until nicely browned. Flip and continue cooking for approximately another 5 minutes. The thickest part of the chicken should reach an internal temperature of 165°F (74°C).
Divide the salad between serving bowls and arrange the warm chicken on top. Drizzle the reserved dressing over the chicken and serve your Greek Chicken Salad immediately.