For the dressing, shake all of the ingredients in a jar until well blended. Chill the dressing until ready to serve.
Heat a grill pan or griddle over medium-high.
For the salad, in a large bowl, toss the lettuce, tomatoes, peppers, onion, cucumber, and parsley.
Season the chicken with salt and pepper, the oregano, granulated garlic, and granulated onion. Drizzle the chicken with EVOO. Grill until cooked through, about 3 minutes per side. Slice the chicken on an angle into thin strips.
Toss the salad with the dressing. Divide among 4 large platters or bowls. Neatly arrange the grilled chicken, feta, olives, and pepperoncini on top. Serve with charred pita bread.
From Rachael Ray Every Day, April 2018.