Balsamic Spinach sauce

I saw this recipe in a magazine and it just jumped out at me and I just had to try it!
We grilled some sirloin steak and I prepared the sauce to go over the top. It was a big hit with our family and I will certainly try it again soon.
Balsamic Spinach Sauce

1 Tbs olive oil
1 lg onion - chopped
1 red pepper - chopped
3 cloves garlic - minced
1 can Cream of Mushroom soup
1/2 cup water
2 Tbs balsamic vinegar
1 Tbs fresh rosemary chopped
7oz bag fresh baby spinach

Heat oil in skillet.
Add onion, pepper and garlic and cook until vegies are tender-crisp, stirring often.
Stir soup, water, vinegar and rosemary in skillet and heat to a boil.
Reduce heat to medium, and stir in spinach
Cover and cook 2 minutes or until desired doneness.