Preheat a grill pan or skillet over medium-high heat.
In a small bowl, mix olive oil, garlic powder, dried oregano, salt, and black pepper.
Brush the chicken breasts with the olive oil mixture on both sides.
Grill the chicken breasts for 5-6 minutes per side or until fully cooked and internal temperature reaches 165°F (75°C).
Remove the chicken from the grill and let it rest for 5 minutes.
Slice the chicken breasts into thin strips.
In a large bowl, combine chopped romaine lettuce, Caesar dressing, grated Parmesan cheese, and fresh lemon juice. Toss gently to coat evenly.
Warm the flour tortillas in a dry skillet or microwave until soft and pliable.
To assemble each taco, place a generous amount of Caesar salad mixture onto the center of each tortilla.
Top the salad with sliced grilled chicken and sprinkle with croutons.
Fold the tortillas in half and serve immediately.