Cut cucumber in half. Use one half in step 3, reserve the other half for tacos in step 5.
For the tzatziki, use a box grater or food processor to shred one half of cucumber. Drain any excess liquid.
In a small bowl, combine grated cucumber, greek yogurt, minced garlic, fresh dill, and lemon juice. Cover and refrigerate for flavors to meld up to 2 hours before serving.
In a medium bowl, combine cucumber, red onion, tomatoes, olives, and feta. Set aside until ready to serve.
To a medium pan, heat olive oil over medium heat. Add garbanzo beans, oregano, onion powder, garlic powder, ground basil, ground dill, salt, and pepper. Stir to evenly coat the garbanzo beans.
Continue to cook the garbanzo beans over medium heat, stirring frequently until cooked through, about 5 minutes.
Once the chickpeas are cooked, keep warm while warming the tortillas. Heat a small pan over medium high heat, gently toast both sides of the tortillas to desired warmth or toastiness.
Evenly divide the garbanzo mixture onto the 8 tortillas. Evenly divide the cucumber mixture and add over the top of garbanzo mixture. Finally, evenly divide the tzatziki and drizzle over the top of tacos.