Slow Cooker Bourbon Portobello Flank Steak Step-by-step instructions

Before you start

Before you start, make sure your slow cooker is clean and ready. Thinly slice the flank steak against the grain into strips about 1/2-inch thick. If the steak is very cold, it’s easier to slice.

Thickly slice the portobello mushrooms and peel the shallots, leaving them whole if they are small, or halving them if large. Measure out the bourbon gravy and cut the butter into pats. Have all the ingredients within reach so you can layer them quickly.

Instructions

Layering for Flavor

1. 1Layer the Ingredients
   Place the sliced flank steak in the bottom of a 6-quart or larger slow cooker. Spread the slices evenly to cover the bottom. Layer the thickly sliced portobello mushrooms over the beef, then scatter the peeled shallots over the mushrooms. Pour the bourbon mushroom gravy over everything, making sure the sauce coats the top. Dot the surface with the butter pats.
   Look for The slow cooker is filled with layers of beef, mushrooms, shallots, and gravy, with butter pats on top.
   Tip For even cooking, try to spread the beef in a single layer as much as possible.
2. 2Cover and Cook Low
   Cover the slow cooker with the lid. Cook on LOW for 6 to 8 hours, or on HIGH for 3 to 4 hours, until the beef is fork-tender and the sauce is bubbling. Avoid lifting the lid during cooking to keep the heat inside. Let it rest for 3 minutes before slicing.
   Look for The sauce is gently bubbling around the edges and the kitchen smells richly savory.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip If possible, cook on LOW for the most tender results.

At the end of this phase, the slow cooker is filled with layers of raw beef, mushrooms, shallots, and gravy. The butter pats sit on top, waiting to melt.

The ingredients are arranged in a neat, even layer, and the gravy covers most of the surface. This is the point where you can see the potential—the rich brown sauce against the dark mushrooms and pale shallots. Everything is ready to cook.

Slow Simmering

3. 3Check for Tenderness
   After the cooking time, check the beef for tenderness. It should shred easily with a fork. If it is still chewy, continue cooking for another 30 minutes and check again. Once tender, let the meat rest in the sauce for at least 3 minutes before serving.
   Look for The beef pulls apart easily and the sauce is thick and glossy.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip If the sauce seems thin, remove the beef and mushrooms, then simmer the sauce on the stovetop to reduce.

After hours of cooking, the slow cooker is bubbling gently. The sauce has darkened and thickened, and the aroma is deeply savory with a hint of bourbon. The beef is visibly tender, and the mushrooms have shrunk slightly, absorbing the sauce. The shallots are translucent and soft. When you stir, the meat easily breaks apart. The kitchen smells incredible, and the meal is almost ready.

Serving the Dish

4. 4Serve Over Rice
   Spoon hot cooked rice onto plates or into bowls. Ladle the beef, mushrooms, shallots, and gravy over the rice. Serve immediately, with extra gravy on the side if desired.
   Look for Steaming servings of beef and gravy over fluffy white rice.
   Tip For a low-carb option, serve over cauliflower rice or with steamed vegetables.

The final phase is all about bringing the dish to the table. The beef is spooned over fluffy rice, with the glossy gravy coating every piece. The mushrooms and shallots are nestled among the meat. The plate is steaming and inviting, with the dark sauce contrasting with the white rice. Every element is tender and flavorful, ready to be enjoyed.

Common mistakes

One common mistake is lifting the lid too often during cooking. Every time the lid is lifted, heat escapes and the cooking time increases. Trust the process and keep the lid on.

Another mistake is using a slow cooker that’s too small—if the ingredients are packed too tightly, they may not cook evenly. Use a 6-quart or larger model. Finally, don’t skip the rest time after cooking. Letting the beef rest in the sauce for a few minutes helps it stay moist and flavorful.

How to tell it’s done

The beef is done when it is fork-tender and easily shreds with a fork. The internal temperature should reach at least 145°F (63°C) for food safety, but slow-cooked beef will be well above that. The sauce should be bubbling gently and slightly thickened.

If the sauce looks thin, remove the beef and mushrooms, then simmer the sauce on the stovetop for a few minutes to reduce. Let the beef rest in the sauce for at least 3 minutes before serving to allow the juices to redistribute.

• Steaks, chops and roasts: 145°F (63°C) in the thickest part, then a 3-minute rest