In a mixing bowl, combine the shredded chicken, mozzarella cheese, garlic powder, oregano, salt, and pepper. Mix well until evenly combined.
In another small bowl, mix the softened butter with the minced garlic. This will be used for spreading on the bread.
Heat a skillet or grill pan over medium heat.
Spread a generous amount of the garlic butter mixture on one side of each slice of bread.
Place two slices of bread, buttered side down, in the skillet. Spoon half of the chicken and cheese mixture onto each slice.
Top each sandwich with the remaining slices of bread, buttered side up.
Cook for about 5-7 minutes on each side, or until the bread is golden brown and the cheese is melted.
Once cooked, remove the sandwiches from the pan and let them rest for a minute before slicing in half.
Garnish with fresh parsley if desired and serve warm.