Season boneless, skinless chicken breasts with garlic powder, salt, and freshly ground pepper. Allow to rest for about 10 minutes.

In a large skillet, place thick-cut bacon over medium heat and cook for 6 to 8 minutes until crispy and golden brown. Transfer to a plate lined with paper towels to drain excess grease.

Using the same skillet with bacon fat, grill seasoned chicken breasts for 6 to 7 minutes on each side until reaching an internal temperature of 165°F. Let chicken rest for 5 minutes before slicing.

Slice flaky croissants horizontally and lightly toast or warm until golden. Brush insides with softened butter.

Assemble the sandwich by layering fresh lettuce, sliced chicken, and crispy bacon on the bottom half of the toasted croissant. Sprinkle with fresh herbs and cap with the top half. Serve immediately.