In a large bowl, combine the cooked orzo, cherry tomatoes, cucumber, red onion, feta cheese, Kalamata olives, pepperoncini, roasted red bell pepper, dill, and parsley.
In a small bowl, whisk together the olive oil, lemon juice, grated garlic, salt, pepper, and oregano. Pour the dressing over the salad and toss until evenly combined. Refrigerate until chilled.
Place the chicken thighs into a zip-top bag and pour in the Italian dressing. Add the salt and mix well to coat the chicken evenly.
Marinate the chicken for several hours or overnight.
Bake at 425°F for 25–35 minutes, or until fully cooked through. The chicken can also be grilled if preferred.
Serve the chicken over the chilled orzo salad.