Grab your marinade ingredients. Mix together 1 cup Greek yogurt, 1/2 lemon juiced, 3 tbs. olive oil, and 2 tsp. dried oregano in a mixing bowl. Season diced chicken with 1 tsp. salt + 1 tsp. black pepper, then add to the marinade. Place into the refrigerator for 30 minutes (up to 4 hours).
If making tzatziki sauce: start by placing the grated cucumber onto a clean kitchen towel. Wrap it up and wring it out over the sink to try and remove as much liquid as possible. Then add to a bowl with the remaining tzatziki ingredients. Place into the refrigerator.
Slice cucumbers and red onions. Wrap bread in damp paper towels and put into the microwave (don't heat just yet).
When the chicken has marinated for at least 30 minutes, pull from the refrigerator. Prep your grill pan by heating it on the stove over medium-high heat and spray with cooking spray. When hot, take tongs and place chicken pieces on the pan, giving each piece space. Grill for 3-4 minutes, then flip pieces and grill another 3-4 minutes until the chicken has cooked through.
Let the chicken cool slightly while you heat pitas for 30 seconds in the microwave. Layer pitas with a few pieces of grilled chicken, cucumber and red onion slices, and tzatziki sauce. Top with feta cheese crumbles and enjoy warm!
Keyword artichoke hearts, basil, cherry tomatoes, chicken, greek chicken, pita bread, red bell peppers, sheet pan chicken, sheet pan meal, tzatziki sauce