Place the chicken strips in a large bowl and sprinkle with the seasonings. Add minced garlic, olive oil, and lemon juice. Mix thoroughly to coat the chicken, then if time allows marinate it in the fridge for up to 1 hour.
Preheat a grill pan over medium-high heat. Grease the grill with a bit of oil, then add chicken and cook until grill marks appear and cooked through, about 8-10 minutes in total.
To prepare the gyros:
While the chicken is cooking, prepare toppings.
Thinly slice the onion, tomatoes, and cucumbers. Microwave the pita bread for about 1 minute. For assembling, load up the pita bread with a spoonful of tzatziki sauce.
Add warm grilled chicken on top of the sauce. Add sliced onion, tomatoes, and cucumbers.
Garnish with fresh dill and serve immediately.
Notes
You don't have to marinate the chicken for an hour but it really does add a lovely depth of flavor.
Make sure to use a preheated grill.
Grease the grill with a bit of oil to prevent the chicken from tearing when you flip it.
You can use flatbread, pita or naan bread.
Feel free to mix in other fresh veggies.
Make sure to make/buy a good amount of tzatziki - better to have too much than too little!