Steak with Spicy Sour Onions

So for the first time, a Willoughby Original!  So we decided to make steak, but wanted to jazz it up!  Here is the recipe.  It was a nice yummy way to do steak.  This way you don't have to use any steak sauce or anything which is healthier.  You might want to go easy on the Red Pepper Flakes unless you can handle the heat because the amount we used really brought it!

Ingredients:
3/4 lb steak (which ever kind you like)
1 tsp Red Pepper Flakes
1 - 2 tablespoons Balsamic Vinegar (depending on taste)
1 Onion sliced
1/4 teaspoon Rosemary

1.) Brown the meat on high heat until cooked until your preferred doneness.  Remove from the pan and set aside to rest

2.) In the same pan (with all the cooked-on steak goodness!) add the onion, Rosemary, red pepper flakes, and as much vinegar are you like.  Cook this for 5 - 10 minutes until everything is married, then serve on top of the steak.