Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes is a hearty and flavorful dish that’s perfect for any occasion. This slow-cooked meal brings together tender flat iron steak, earthy portobello mushrooms, and creamy potatoes for a comforting experience. Whether you’re hosting a family gathering or simply enjoying a quiet night at home, this recipe will impress your guests and satisfy your cravings.
Why You’ll Love This Recipe
- Easy to Prepare: With just a few simple steps, you can set it and forget it! The crock pot does all the work while you enjoy your day.
- Rich Flavor: The combination of beef broth, onions, and mushrooms creates a savory sauce that enhances the flavor of the flat iron steak.
- Versatile Ingredients: Use whatever vegetables you have on hand. Carrots or green beans could easily be added to this dish.
- Perfect for Meal Prep: Make a big batch and enjoy leftovers throughout the week. The flavors only get better with time!
- Family-Friendly: This dish is sure to please even the pickiest eaters in your household.
Tools and Preparation
To create the perfect Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes, you’ll need some essential tools. Having the right equipment makes cooking easier and more enjoyable.
Essential Tools and Equipment
- Crockpot
- Knife
- Cutting board
- Measuring cup
- Spoon for stirring
Importance of Each Tool
- Crockpot: The star of this recipe! It allows for slow cooking which makes the steak tender.
- Knife: A sharp knife helps you slice through vegetables quickly and safely.
- Cutting board: Provides a safe surface to chop ingredients without damaging your countertops.
Ingredients
Easy and delicious flat iron steak done in the slow cooker with portobello mushrooms and potatoes.
For the Meat
- 2-3 pounds of flat iron steak
For the Vegetables
- 1 pound of sliced portobello mushrooms
- 1 large white onion sliced into large rings
- 3-4 large red potatoes washed and chopped into 1 pieces with skin still on
For Cooking
- 1 cup beef broth
- butter for greasing crockpot
How to Make Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes
Step 1: Grease the Crockpot
Start by greasing the interior of your crockpot with a generous amount of butter. This step prevents sticking and adds flavor to your dish.
Step 2: Add the Steak
Place the flat iron steak in the bottom of the crockpot. Ensure it lies flat so it cooks evenly.
Step 3: Layer the Vegetables
Next, layer the sliced portobello mushrooms, onion rings, and chopped red potatoes over the steak. This layering helps infuse all ingredients with flavor while cooking.
Step 4: Pour in Beef Broth
Pour 1 cup of beef broth over everything in the crockpot. This broth will keep everything moist during cooking.
Step 5: Cook It Slow
Cover your crockpot and cook on low for 6-8 hours. You’ll know it’s ready when the potatoes are tender.
Step 6: Serve and Enjoy!
Once cooked, gently stir everything together before serving. Enjoy your delicious Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes!
How to Serve Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes
Serving your Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes can elevate the dining experience. Pairing this dish with the right accompaniments enhances its rich flavors and makes for a delightful meal.
Serve with Fresh Herbs
- Garnish your dish with fresh parsley or chives for an added layer of flavor and color.
Add a Side Salad
- A crisp green salad can provide a refreshing contrast to the hearty steak and mushrooms.
Pair with Crusty Bread
- Serve some warm, crusty bread on the side to soak up the delicious juices from the crock pot.
Include a Creamy Sauce
- A dollop of horseradish cream or garlic aioli can complement the steak beautifully.
Offer Pickled Vegetables
- Pickled cucumbers or onions add a tangy crunch that balances the richness of the steak.

How to Perfect Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes
To ensure your Crock Pot Flat Iron Steak turns out perfectly every time, consider these helpful tips.
- Choose Quality Meat: Opt for high-quality flat iron steak for better flavor and tenderness.
- Cut Vegetables Uniformly: Chop potatoes and mushrooms into similar sizes to ensure even cooking.
- Season Generously: Don’t hold back on seasoning; it enhances the overall taste of the dish.
- Avoid Overcrowding: Ensure there is enough space in the crock pot for steam circulation; overcrowding can lead to uneven cooking.
Best Side Dishes for Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes
Complementing your main dish with tasty side dishes can make your meal even more enjoyable. Here are some great options to consider:
- Garlic Mashed Potatoes: Creamy mashed potatoes seasoned with garlic make a perfect pairing.
- Roasted Asparagus: Lightly seasoned asparagus brings a fresh crunch that complements the richness of the steak.
- Coleslaw: A tangy slaw provides a refreshing contrast to the savory flavors of the main dish.
- Steamed Broccoli: Bright green broccoli adds color and nutrition while balancing out heavier elements.
- Baked Sweet Potatoes: The sweetness of baked sweet potatoes contrasts nicely with savory steak flavors.
- Quinoa Salad: A light quinoa salad dressed in lemon vinaigrette offers a healthy grain option.
Common Mistakes to Avoid
When making Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes, certain mistakes can impact your dish’s outcome. Here are a few common pitfalls to avoid.
- Not greasing the crockpot – Failing to grease the crockpot can lead to sticking, making clean-up difficult. Always use butter or cooking spray to prevent this issue.
- Using low-quality steak – Opting for low-quality flat iron steak can affect the flavor. Choose a well-marbled cut for a tender and juicy result.
- Overcooking the ingredients – Cooking for too long may cause the steak and vegetables to become mushy. Stick to the recommended cooking time of 6-8 hours.
- Skipping the beef broth – Omitting broth can lead to dry meat. Always include beef broth to enhance moisture and flavor in your dish.
- Chopping potatoes too small – Cutting potatoes into smaller pieces can lead to them disintegrating during cooking. Keep them large enough for better texture.

Storage & Reheating Instructions
Refrigerator Storage
- Store leftovers in an airtight container.
- Refrigerate within 2 hours of cooking.
- Use within 3-4 days for best quality.
Freezing Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes
- Allow the dish to cool completely before freezing.
- Store in freezer-safe containers or bags.
- Consume within 2-3 months for optimal flavor.
Reheating Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes
- Oven – Preheat oven to 350°F (175°C). Place in an oven-safe dish, cover, and heat for about 20 minutes.
- Microwave – Transfer a portion to a microwave-safe bowl. Heat in short intervals, stirring in between, until warmed through.
- Stovetop – In a pan over medium heat, add a little broth if needed, and stir until heated completely.
Frequently Asked Questions
What is the best cut of meat for this recipe?
The focus keyphrase is essential here as flat iron steak is highly recommended due to its tenderness and flavor when cooked slowly.
Can I use other types of mushrooms?
Yes! While portobello mushrooms work great, you can substitute with cremini or button mushrooms for different flavors.
How do I know when my steak is done?
For perfectly cooked flat iron steak, check that it is fork-tender after 6-8 hours on low heat in your crockpot.
Can I customize the vegetables used?
Absolutely! Feel free to add or substitute other vegetables like carrots or green beans based on your preference.
Final Thoughts
This Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes recipe is not only easy but also incredibly versatile. You can customize it by adding different vegetables or spices according to your taste. Try it out for a comforting family meal that everyone will love!
PrintCrock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes
Crock Pot Flat Iron Steak with Portobello Mushrooms and Potatoes is a savory and satisfying dish that embodies comfort food at its finest. This easy-to-make recipe combines tender flat iron steak, earthy portobello mushrooms, and creamy potatoes in a slow cooker, allowing the flavors to meld beautifully over time. Perfect for family gatherings or cozy dinners at home, this meal not only pleases the palate but also offers the convenience of a set-it-and-forget-it approach. Whether served as a centerpiece for your dinner table or enjoyed as leftovers throughout the week, this dish is sure to become a favorite.
- Prep Time: 15 minutes
- Cook Time: 6-8 hours
- Total Time: 0 hours
- Yield: Serves approximately 6 people
- Category: Dinner
- Method: Slow Cooking
- Cuisine: American
Ingredients
- 2-3 pounds flat iron steak
- 1 pound portobello mushrooms (sliced)
- 1 large white onion (sliced into rings)
- 3-4 large red potatoes (chopped into wedges)
- 1 cup beef broth
- Butter (for greasing)
Instructions
- Grease the crockpot with butter to prevent sticking.
- Place the flat iron steak at the bottom of the crockpot.
- Layer sliced mushrooms, onion rings, and chopped potatoes on top of the steak.
- Pour beef broth over all ingredients to keep them moist during cooking.
- Cover and cook on low for 6-8 hours until everything is tender.
- Stir gently before serving and enjoy your hearty meal!
Nutrition
- Serving Size: 1 plate (approximately 300g)
- Calories: 440
- Sugar: 2g
- Sodium: 650mg
- Fat: 24g
- Saturated Fat: 10g
- Unsaturated Fat: 12g
- Trans Fat: 0g
- Carbohydrates: 30g
- Fiber: 4g
- Protein: 32g
- Cholesterol: 90mg