Creating the Sheet Pan Chicken Shawarma Havarti Sandwich is simple. Follow these steps to ensure a delicious result:

1. Preheat Oven: Preheat your oven to 400°F (200°C) to prepare for roasting.

2. Prepare Marinade: In a mixing bowl, combine olive oil, cumin, paprika, coriander, turmeric, garlic powder, onion powder, salt, and black pepper.

3. Marinate Chicken: Add chicken thighs to the marinade, ensuring they are well-coated. Allow them to marinate for at least 10 minutes for maximum flavor. For best results, marinate for 30 minutes or longer.

4. Arrange on Sheet Pan: Place the marinated chicken thighs in a single layer on a sheet pan lined with parchment paper. This will ease cleanup later on.

5. Roast Chicken: Roast the chicken in the preheated oven for 20-25 minutes or until fully cooked and the internal temperature reaches 165°F (75°C).

6. Add Cheese: Before the chicken finishes cooking, add the slices of Havarti cheese on top of the chicken during the last 5 minutes of cooking. Return it to the oven until the cheese is melted and bubbly.

7. Prepare Toppings: While the chicken is cooking, chop the cucumber, halve the cherry tomatoes, and slice the red onion.

8. Warm Pita or Rolls: If desired, warm the pita breads or hoagie rolls in the oven for about 2-3 minutes for a toasted experience.

9. Assemble Sandwich: Once the chicken is done cooking, remove it from the oven. Slice the chicken into strips and place it inside the pita or rolls.

10. Top it Off: Add the chopped cucumber, halved cherry tomatoes, sliced red onion, and drizzle tahini sauce over the top.

11. Garnish and Serve: Sprinkle fresh parsley or cilantro on top for an extra burst of flavor. Serve immediately, and enjoy your amazing sandwich!