Rub the chicken breasts with olive oil, garlic powder, paprika, salt, and black pepper.
Grill or cook the chicken breasts for 6-8 minutes per side, or until fully cooked and juices run clear. Remove from heat and let rest for 5 minutes before slicing into thin strips.
Butter one side of each bread slice lightly. Toast the bread slices on a skillet or grill until golden and crispy, about 1-2 minutes per side.
Spread halal Caesar dressing evenly on the unbuttered sides of all bread slices.
Layer the bottom slice of bread with romaine lettuce leaves, sliced chicken breast, cherry tomatoes, and grated Parmesan cheese.
Top with the second slice of bread, dressing-side down, to complete the sandwich.
Slice the sandwich in half and serve immediately.
Notes
For a spicier flavor, add a pinch of cayenne pepper to the chicken seasoning. You can substitute ciabatta bread with whole-grain bread for a healthier option.