Make the fries. If you're making your fries from scratch, chop your potatoes into thin fries. I don't peel the potatoes - but you can if you like. Pop them into a large bowl, then toss with 1 tablespoon of olive oil, 1 teaspoon smoked paprika, 1 teaspoon of dried oregano, and 1 teaspoon of salt. Arrange in your air fryer basket, then air fry at 400°F (200°C) for 15 to 20 minutes, shaking them at the halfway mark, until gorgeously golden and crispy. If you're using frozen fries, cook them according to their packet instructions.
Prepare the chicken gyros mixture. To a large mixing bowl, add the ground chicken, 1 tablespoon of lemon juice, minced garlic, 1 teaspoon each of dried thyme, dried oregano, smoked paprika, ground cumin, and salt, a good grind of black pepper, and the chopped flat-leaf parsley. Mix until well combined.
Top the tacos. Spread a heaped tablespoon of the chicken mixture into a thin layer on each of your mini tortillas. Use the back of your spoon to spread the chicken right to the edges of the tortilla, trying to make it as even as possible.
Cook the tacos. Set a large skillet or frying pan over medium-high heat. Drizzle a little olive oil into the pan, then place the tacos, chicken side down, into the pan. Use a spatula to really press down on the back of the taco to 'smash' it into the pan. This ensures even, quick cooking and helps the meat stick to the tortilla. Cook for four minutes, then flip and cook for a further minute on the other side. You should be able to cook a couple of tacos at the same time. Repeat with the remaining tacos.
Top the tacos. Dollop a heaped spoonful of tzatziki onto each taco, then add a couple of fries, the diced tomatoes and cucumber. Finish with a sprinkling of creamy feta and a scattering of flat-leaf parsley.