Melt 2 tablespoons of butter in a skillet over medium low. Toss in the chopped mushrooms and cook for about 5 minutes or until mushrooms are slightly browned.

Add the minced garlic and the remaining tablespoon of butter.

Add in the baby spinach immediately. The spinach will at first look like it won't fit in the pan, but after a few minutes it will shrink down tremendously. Stir everything several times. Add some salt and pepper if desired.

Cook another 3-5 minutes, stirring frequently.