Slice onion and sauté in 1 tbsp. of butter. Set aside.
Melt the remaining 1 tbsp. butter.
Cover bread evenly on both sides with butter, and lightly brown.
Set bread on plate, begin building sandwiches.
While cooking the meat, Assemble the following as you have time.
Add avocado on one piece of bread.
Place onion evenly on the avocado.
Add honey mustard to the other slice of bread.
Place spinach on the slice with the honey mustard.
Cook salami on medium heat until grease begins to melt.
Put pepperoni on salami, and flip to heat the pepperoni.
Put ham on the salami, and flip to heat the ham.
Flip again, and place the meat on the spinach.
Put the two sides together.