Preheat oven to 400 degrees
Rinse chickpeas, toss with Greek seasoning and olive oil. Place in oven for 25 minutes.
Make Tzatziki sauce by chopping the cucumber and the garlic and mixing it with the rest of the ingredients in the tzatziki sauce.
Remove the chickpeas out of the oven and cool.
Warm pita bread, cut lettuce and tomato.
Assemble your gyros. place some Tzatziki sauce on pita bread. top with chickpeas, lettuce, and tomato.