In a large bowl, combine the Greek yogurt, paprika, oregano, coriander, cumin, garlic, cayenne, cinnamon, pepper, tahini, olive oil, and salt.
Add the chicken and stir to coat completely in the sauce. Cover with plastic wrap and marinate in the fridge for at least 30 minutes or up to 4 hours.
Preheat the oven to 400˚F (200˚C).
Make the tzatziki: in a medium bowl, combine the Greek yogurt, cucumber, lemon zest, garlic, dill, pepper, salt, olive oil, and lemon juice. Stir to combine. Cover and refrigerate until ready to use.
Thread 3-5 pieces of chicken onto each wooden skewer until loosely filled, leaving at least an inch (2 cm) of space on either end of the skewers. Place the skewers on a baking sheet and bake for 20 minutes.
Slice the dinner rolls in half. Place the bottom half on a greased baking sheet. Sprinkle with diced tomatoes and chopped red onion.
Stick the par-cooked chicken skewers into the bottom buns, spacing evenly. Place the top buns over the skewers and press down.
Combine the olive oil, garlic, parsley, and salt in a small bowl and brush on the top buns.
Bake the buns and the chicken for 10 more minutes, or until the chicken is fully cooked and the bread is toasted.
Place the gyro sliders on a large platter and serve with tzatziki.