Step 2

Mix together the garlic powder, onion powder, paprika, thyme, oregano, salt, and cayenne in a rimmed dish or pie plate, set aside.

Step 3

Pour the melted butter into a separate rimmed dish or pie plate. Pat the chicken dry with paper towels and dip into the melted butter, flipping over to coat the chicken then lay into the spice mix and flip to coat in the spices.

Step 4

Heat a large cast-iron skillet over medium-high heat. When the pan is hot add the the oil and tilt to coat the bottom of the pan evenly with oil. Add the chicken breasts to the pan, in batches if necessary, and cook until chicken is darkened and cooked through, 5 to 6 minutes per side. Transfer cooked chicken to a plate and set aside.

Step 5

Mash the avocado in a bowl with a fork, add the mayonnaise, lime juice, and salt and mix until well combined.

Step 6

Place the blackened chicken breast into your rolls and top with sliced onion, lettuce, and the Avocado Mayo..