Better-Than-Expected Marsala Butter Sauce

Welcome to Brittany’s Steakhouse. We have one entree on the menu today: this sirloin steak topped with a marsala-butter sauce. Take it or leave it, but if you’re smart, you will take it.
I thawed these frozen steaks in the frige all day yesterday, knowing that I would make them for dinner. It wasn’t until about half way through the day that I realized I have never cooked a steak. I had no idea how I would add some flavor since it was too late to try a marinade and I wasn’t about to use a store-bought sauce. 
When I got home and found a bottle of Marsala wine sauce from this pasta awhile back, I started feeling adventurous. 
I honestly had no idea what I was doing. Melt a little butter. Throw in some onions. Parsley? That sounds good. A dash of this and a shake of that….
Giving Greg a fair warning that this might not be so good, we were both surprised with the outcome. 

What was left after my experimenting was a sweet, buttery sauce that I will now use all the time.
I had broiled the steaks for about 18 minutes then topped them with the sauce immediately after pulling them out of the oven. Sauteed broccoli and steamed brown rice on the side made for one delicious meal. 
Marsala Butter Steak Sauce
Makes about 2 servings
1/4 cup butter or margarine 
1/3 cup onion, chopped
1/4 cup Marsala wine sauce
2 tablespoons milk
1 teaspoon chopped parsley flakes
1/4 teaspoon black pepper
1. Heat butter in a small skillet over medium heat.
2. Once butter is melted, add onion and cook about 5 minutes, stirring occasionally. Add Marsala, stir and continue to cook until simmering.
3. Stir in milk. Add parsley and pepper. Stir for another 3-4 minutes.
4. Remove from heat. Let stand about two minutes. Spoon sauce over cooked steaks.