Season the boneless skinless chicken breasts with salt and pepper on both sides. Heat a skillet over medium-high heat with a splash of olive oil. Cook the chicken for 6-7 minutes on each side until it’s golden brown and fully cooked, reaching an internal temperature of 165°F. Remove the chicken from the skillet and let it rest for a few minutes to maintain juiciness.

While the chicken is resting, slice the avocado in half, remove the pit, and scoop the flesh into thin slices. Next, prepare your other ingredients by slicing the cheese, red onion, and tomato.

Take your favorite bread and spread mayonnaise and Dijon mustard evenly over one side of each slice. Start layering the sandwich by placing the sliced chicken on one piece of bread, followed by the avocado slices, cheese, red onion, and tomato. Top it off with the remaining slice of bread.

In the same skillet, melt a tablespoon of butter or add a drizzle of olive oil over medium heat. Carefully place the assembled Chicken Avocado Melt Sandwich into the skillet, grilling each side for 3-4 minutes.

Once both sides of the sandwich are toasted and the cheese is gooey, remove it from the skillet and let it cool slightly. Slice the Chicken Avocado Melt Sandwich in half to reveal the layers of flavor.