Preheat your grill or skillet over medium heat. Season chicken breasts with salt and pepper. Cook for about 6 minutes on each side until golden brown and fully cooked.

While the chicken cooks, scoop out the avocados into a bowl, adding salt and pepper to taste. Mash until creamy.

Slice the cooked chicken into thin strips.

Assemble the sandwich by spreading mashed avocado on one slice of bread, layering with chicken strips, and topping with shredded cheddar cheese.

Drizzle olive oil on both sides of the sandwich and grill for about 3 minutes per side until golden brown and cheese is melted.

Slice diagonally and serve warm.