1. Prepare the Chicken (if not using pre-cooked): If you’re starting with raw chicken, dice it into small, bite-sized pieces. Heat 1 teaspoon of olive oil in a skillet over medium-high heat. Add the chicken and season with paprika, onion powder, oregano, salt, pepper, and red pepper flakes (if using). Cook for 5-7 minutes, or until the chicken is cooked through and lightly browned. Set aside. If using pre-cooked or rotisserie chicken, simply shred or dice it and place it in a bowl. You can toss it with the same seasonings for extra flavor.

2. Preheat Oven: Preheat your oven to 375°F (190°C). Line a large baking sheet with parchment paper or aluminum foil for easier cleanup.

3. Make Garlic Butter: In a small bowl, combine the softened butter, minced garlic, chopped fresh parsley, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Mix well until everything is thoroughly incorporated. If your butter is too firm, you can microwave it for 10-15 seconds, but be careful not to melt it completely.

4. Prepare the Garlic Bread Base: Slice the loaf of bread in half horizontally, like you would for a sub sandwich. If the loaf is very thick, you might want to scoop out some of the soft interior bread from both halves to make more room for the filling, but this is optional.

5. Apply Garlic Butter: Generously spread the garlic butter mixture evenly over the cut surfaces of both halves of the bread. Ensure you get good coverage, especially near the edges, for maximum flavor and crispiness.

6. Initial Bake for Garlic Bread: Place the bread halves, butter-side up, on the prepared baking sheet. Bake for 8-10 minutes, or until the butter is melted and the bread is lightly toasted and fragrant. Keep a close eye on it to prevent burning, especially the garlic.

7. Assemble the Sandwich – Chicken Layer: Remove the bread from the oven. On the bottom half of the garlic bread, evenly distribute the cooked and seasoned chicken. Make sure it covers the surface well.

8. Add Sauce (Optional): If you’re using marinara sauce, you can either spread a thin layer over the chicken or reserve it for dipping later. Some people prefer it inside, others on the side. For this recipe, let’s assume a light spread over the chicken for extra moisture and flavor.

9. Cheese It Up: Generously sprinkle the shredded mozzarella and cheddar cheese over the chicken layer. Don’t be shy with the cheese – this is a “Cheesy” Chicken Garlic Bread Sandwich, after all! Finish with a sprinkle of grated Parmesan cheese for an extra savory kick.

10. Return to Oven: Carefully place the top half of the garlic bread over the cheese-covered chicken. You can leave it open-faced for meltier cheese on top, or close it like a traditional sandwich. For this recipe, let’s go with placing the top half on.

11. Final Bake: Return the assembled sandwich to the oven. Bake for another 10-15 minutes, or until the cheese is fully melted, bubbly, and slightly golden brown, and the sandwich is heated through. If you left it open-faced, the cheese will brown more. If closed, the internal heat will melt everything beautifully.

12. Rest and Garnish: Once baked to perfection, carefully remove the sandwich from the oven. Let it rest for 5 minutes before slicing. This helps the cheese set a bit and makes it easier to cut. Garnish with additional fresh parsley if desired.

13. Slice and Serve: Using a sharp serrated knife, slice the Cheesy Chicken Garlic Bread Sandwich into individual portions. Serve immediately while it’s hot and gooey. Enjoy with extra marinara sauce for dipping, if you like.