Preheat the oven or air fryer to 200 degrees Celcius.
Combine cauliflower with chili powder, paprika powder, chili flakes and sea salt. Mix to combine, making sure all of the cauliflower florets are covered in seasoning.
Place in the oven or air fryer and roast for 14-18 minutes, until tender and golden brown. Stir once or twice.
Slice the sweet potatoes into thin stripes and drizzle with just a little bit of olive oil. Bake in the oven or air fryer together with the cauliflower for about 10-15 minutes. Stir once or twice.
Meanwhile preheat a nonstick pan over medium heat and fry the bell pepper until warm and fry marks start to form (you can also make it in the oven or air fryer).
Core the cucumber and grate, squeeze out as much excess water as possible. Combine with greek yogurt, lemon juice, garlic, salt and pepper.
Then just 1-2 minutes remain for the cauliflower and sweet potatoes, cut the pita breads in half and add to the warm frying pan, fry for 1-2 minutes, until golden brown.
Assembly the pita bread by adding lettuce, cauliflower, bell pepper and red onion. Top with crumbled pita and tsatsiki. Serve with fries on the side or stack some fries into the pitas as well.