Place the drained chickpeas on a large paper towel. Do your best to dry them thoroughly.
Heat the oil in a large skillet over medium high heat. Once the oil is sizzling add the chickpeas and the diced onion to the pan and season with salt and pepper.
Cook the chickpeas for 5-8 minutes, stirring frequently (to prevent them from burning).
Reduce heat to medium and add the oregano, rosemary, and garlic powder. Stir to combine until the chickpeas are evenly covered. Continue cooking the chickpeas until they are crispy but not burned.
Remove from heat and serve the chickpeas on Greek flatbread topped with tzatziki sauce, cucumbers, chopped tomatoes and crumbled feta cheese.
Notes
Alternatively, you can leave out the diced onion when cooking the chickpeas and add raw onions for topping the gyros. (But I'm not the biggest fan of raw onion, so I opted to cook them with the chickpeas). Nutrition facts based per serving. Nutrition facts does not include the "for serving" ingredients.