Dice the onions.
1 small onion
Add 1 tablespoon of butter to a medium pan, then add the mushrooms and onions. Cook for 5-8 minutes.
2 tablespoon butter, 8 ounces sliced white mushrooms
Remove the mushroom mixture and put it in a bowl.
Clean out the pan then spread some melted butter on the bottom. Add two tortillas to the pan (half in and half out over the side).
2 burrito style tortillas
Layer each tortilla with half the shredded cheese, the mushrooms, then more cheese.
1 cup shredded swiss cheese
Close the other half of the tortilla over the top and brush with butter.
2 tablespoon butter
Cook over medium/high heat for 5 minutes.
Flip and cook for another 2-3 minutes, or until cheese is melted.
Split the soup into two bowls and serve each soup with a quesadilla. Enjoy!