Add mushrooms and onions to hot skillet along with an additional Tablespoon of butter and a sprinkle of salt. Cook for 4-5 minutes until mushrooms and onions are soft. Add wine and broth and simmer for 7-10 minutes until liquid reduces to half. Add sour cream and mix well. Thicken with E-Z Gel. Add additional salt and pepper if needed. Depending on the salt level of your beef broth you may not need any salt at all.