Place the chicken in a bowl with the oregano, garlic, lemon, red wine vinegar, olive oil, salt, and pepper; mix and marinate in the fridge for at least 30 minutes
Mix together the ingredients for the tzatziki and set aside in the fridge
Skewer the chicken on 4 skewers and then preheat a grill pan (or pan) over medium high heat; add oil and sear chicken for 4-6 mins per side until cooked through
Heat pita in a lightly oiled pan over medium-high heat for 30 secs - 1 min per side then spread on a thin layer of tzatziki; add cucumber, onion, tomato, and the chicken souvlaki
Top with more tzatziki and fresh dill, a squeeze of lemon juice and enjoy!