Grill chicken breast in skillet over medium-high heat with 1 Tbsp olive oil. Flip frequently and use a pinch of salt and pepper as desired. Once fully cooked, shred chicken using fork.
In separate large skillet (or panini pan), spray nonstick cooking spray and heat to medium-high heat. Place two slices wheat bread onto skillet and cook until lightly browned. Then add the chicken and sliced avocado to one slice, drizzling the buffalo sauce on top.
Place the other slice of bread on top and press firmly down with spatula. Flip until golden brown. Enjoy! If short on time, you could toast the bread in a toaster and assemble the sandwiches this way.