In a large shallow bowl, whisk lemon juice, olive oil, garlic, and spices until smooth. Add chicken to marinade and turn to evenly coat. Cover bowl and marinate chicken in refrigerator at least 2 hours or up to 12.
Preheat oven to 400F and lightly grease a large sheet pan. Remove chicken from marinade and discard marinade. Arrange chicken and sliced onion in a single layer on sheet pan.
Roast chicken at 400F 10-15 minutes until chicken registers 165F and onions are tender. Toss parsley into chicken and onions and set aside for a moment.
Roasted Red Pepper Tzatziki
Place Greek yogurt and 1/2 cup roasted red peppers in a food processor. Pulse several times until completely smooth.
Scrape yogurt into a medium bowl and stir in remaining diced roasted red peppers, cucumber, garlic, lemon juice, parsley, mint, paprika, and salt and pepper to taste. Refrigerate until ready to use.
Salad
Assemble the salad by placing spring greens in a large serving bowl and arranging diced chicken and onions over top along with cucumber, cherry tomatoes, and feta. Drizzle tzatziki over top and serve salad with flatbread wedges. Enjoy!
Notes
Storing InstructionsSalad is best if served immediately after assembly.