Stir together first 5 ingredients. Spread avocado mixture evenly on 1 side of each of 4 bread slices. Top each evenly with ham, next 4 ingredients, and remaining bread slices. Spread butter on both sides of each sandwich.
Cook sandwiches in a nonstick skillet or on a griddle over medium heat 6 minutes on each side or until golden.
This sandwich is delicious! I made it according to recipe except that I used white bread I had made instead of wheat. Will make again for sure!