I toast the GF bread (you can use bread of your choice) and wait for it to cool completely. Slather it with mayo or omit mayo if you so not care for it. Slice your avocado, I recommend thinly and layer the avocado, easier to bite through. Top with pickled onions and sprinkle with salt and pepper. Letting the bread cool before you add toppings helps to keep it crunchy and not get soggy.