Mushroom Onion Burger

Here's another topping for a burger...mushrooms and onions...just add your favorite cheese and condiments....I like provolone and Dijon mustard and you're set to go!

3 Tbl butter
1 medium onion, thinly sliced
8 ounces sliced mushrooms of your choice
1/2 tsp salt
1/4 tsp black pepper

In a large saute pan, melt the butter , add the onions and saute on medium low heat until the onions just begin to caramelize a bit.  Add the sliced mushrooms, raise the heat and continue to saute until the mushrooms are softened and start to brown a bit.  Stir in the salt and pepper.  Makes enough for 4 to 6 burgers.