Cut the chicken into small, square pieces while partially frozen for easier cutting.

Fry the chicken in a pan until cooked through.

Add water and fajita seasoning to the pan with the chicken and simmer until the sauce thickens slightly.

Set the cooked chicken aside.

Butter one side of each fajita shell.

Dice the tomato and onion, then mix together and set aside.

Shred the Cheddar/mozzarella cheese mix and set aside.

Heat a pan or griddle to approximately 350 degrees Fahrenheit.

Place one buttered fajita shell, butter-side down, on the hot surface.

Sprinkle a generous amount of cheese on the shell.

Add 1/4 to 1/2 cup of the chicken mixture on top of the cheese.

Add about 1/4 cup of the tomato and onion mix.

Sprinkle more cheese generously over the tomato and onion mix.

Top with another fajita shell, butter-side up.

Cook until the cheese starts to bubble and melt.

Flip the quesadilla carefully, pressing down with a spatula if the center is plump.

Cook until the shell is golden brown and crispy.

Let the quesadilla stand for a few moments, then cut it into quarters.

Serve with sour cream, guacamole, or salsa for dipping.