Pre-heat the oven to 425 degrees. Line a baking sheet with parchment paper.
Pat-dry chicken with a sheet of paper towel. Transfer the chicken and chickpeas onto the baking sheet and make sure that they are on a single layer.
Drizzle them with olive oil and sprinkle them with coriander, cumin, salt and pepper.
Rub all sides of the chicken and chickpeas with the spices either with your clean hands or using a spatula and/or tongs (to flip the chicken).
Roast for 15 minutes or until the chicken is fully cooked (it should register between 160-165 F degrees when a thermometer is inserted in the middle of a thigh).
Let rest for 10 minutes. Cut chicken into strips.
When ready to assemble, lightly toast a pita bread and place it on a plate. Spread it with a few tablespoons of tzatziki sauce and top it off with chicken strips, a handful of roasted chickpeas, and arugula. If preferred, drizzle it with more Tzatziki sauce and garnish with fresh dill. Lightly sprinkle with salt and pepper.
Repeat the same process for the rest of the pita bread.