2. Brush the chicken breasts with olive oil and season with salt and black pepper.
3. Grill the chicken breasts for about 6-7 minutes on each side, or until fully cooked.
4. Toast the burger buns on the grill for a minute or until golden brown.
5. Assemble the sandwich by placing the grilled chicken on the bottom bun, followed by lettuce, tomato, and cheese (if using). Top with the other half of the bun.