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Slow Cooker Flank Steak in Mushroom Sauce

Slow Cooker Flank Steak in Mushroom Sauce

How to make Slow Cooker Flank Steak in Mushroom Sauce ?
Course Dinner
Cuisine international
Prep Time 10 minutes
Cook Time 11 hours
Total Time 11 hours 10 minutes
Servings 4 people
Calories 380kcal


  • 1 1/2 lbs flank steak
  • 1/4 cup sauterne wine or any sweet wine that you find drinkable
  • 1 tbs soy sauce
  • 2 cloves of garlic, crushed
  • 1 14.5 oz can of beef broth or consomme
  • 1 tsp sauce seasoning such as Kitchen Bouquet®
  • 1 tbls ketchup
  • 1 tsp prepared mustard
  • 8 fresh mushrooms, washed and halved
  • 2 tbs cornstarch
  • 2 tbs water


  • Place steak in bottom of slow cooker. (Often times I will brown
    the meat prior to lining it in the bottom of the crock pot, but there
    is no hard fast rule that says you must do this). 
  • Combine wine, soy sauce, garlic, beef broth, sauce seasoning, ketchup and mustard. Pour over the steak. Add the mushrooms. Cover and cook on low for 6 to 8 hours. I find that the shorter cooking time is usually the norm due to the thinner cuts of flank steak you usually find in the markets now a days.
  • When meat is cooked, dissolve cornstarch in water. Stir cornstarch into crock pot, cover and cook another 10 minutes or until sauce has thickened to your liking. Pair this tasty steak with mashed potatoes and a green salad with ranch dressing.