Put the chicken in a heatproof container and sprinkle with salt, pepper, and sake. Cover with plastic wrap and microwave for about 2 minutes at 600 W.
Cube the avocado, sprinkle with lemon juice and mix.
Cut the chicken into easy to eat pieces (or shred it with your hands).
Put the well drained yogurt and wasabi in a bowl, and mix together. Add the avocado and chicken from Step 2 and combine.
Taste, and adjust the seasoning with salt and pepper.
I changed the main photo. I used pita bread instead of sliced bread.
You can serve the filling as a salad too.
Story Behind this Recipe
I used yogurt instead of mayonnaise to try to make this sandwich healthier, and the combination with wasabi was surprisingly good. So I wrote it up as a recipe.
If you're just making 2 sandwiches 1/2 of the avocado will be left over. If you're not using the other half right away, store with the pit still in it. That is supposed to stop the avocado from going brown. But please try to use it up as soon as possible in any case. Adjust the cooking time for the chicken depending on your microwave.