Mushrooms. Trim the stem very end of each mushroom. Slice the cap and stem into 1/4" slices (about 4-5 slices per cap) and then in half.
4 Tablespoons salted butter divided
Green Onions. Cut the green onions on an angle, into 1" pieces. Set aside.
1 cup green onions (about 1 bunch)
Beef Broth. I highly recommend using a paste to make your broth. Mix the paste into the water and set aside. Remember, double up on the paste.
2 teaspoons beef broth paste to make 1 cup of broth
Butter. To the skillet, add 2 Tablespoons of butter. Over medium low heat, melt the butter. Add the mushrooms and salt. Cook for 7-8 minutes until the mushrooms are completely cooked, soft, and a rich brown color. The liquids should be mostly gone.
12 ounce whole baby bell a mushrooms, 1/2 teaspoon sea salt
More Butta'. Make room in the center of the pan. To the skillet at the remaining 2 Tablespoons of butter. Over low heat, melt the butter completely.
Flour. Whisk the flour into the butter until well combined. Allow the flour and butter to cook for 1-2 minutes, continue to whisk.
2 Tablespoons flour
Liquids. Add the Marsala wine and beef broth to the sauce. Continue to whisk until the sauce begins to thicken.
1/4 cup Marsala wine or substitute with more beef broth
Green Onions. Add the green onions and cook for 1-2 minutes until the green onions soften.