Preheat your grill to medium-high heat. If using a grill pan, heat it over medium-high heat on the stove.
In a small bowl, mix together garlic powder, onion powder, smoked paprika, salt, and black pepper. Rub the spice mixture evenly over both sides of the chicken breasts.
Drizzle olive oil over the chicken breasts and ensure they are well coated.
Place the chicken on the grill and cook for about 6-7 minutes on each side, or until the internal temperature reaches 165°F. Remove from the grill and let rest for 5 minutes.
While the chicken is resting, in a small bowl, combine mayonnaise, chipotle sauce, and lime juice. Mix well to create the chipotle mayo.
Slice the grilled chicken breasts into strips. Toast the sandwich rolls on the grill for about 1-2 minutes until golden brown.
Assemble the sandwiches by spreading a generous amount of chipotle mayo on the bottom half of each roll. Layer with lettuce, sliced tomato, grilled chicken, and avocado. Top with the other half of the roll.
Serve immediately and enjoy your delicious grilled chicken sandwich!