This slow cooker pepper steak combines three pounds of flank steak, four bell peppers and two onions in a savory-sweet sauce. Allow 20 minutes to prepare it and about six hours on Low, adding the peppers and onions for the final 90 minutes.
This Slow Cooker Pepper Steak pairs strips of tender flank steak with all the colors of bell peppers and onions in a savory-sweet soy-brown sugar-garlic sauce. The slow-cooked beef soaks up the flavorful sauce and goes melt-in-your-mouth tender, while the bell peppers and onions keep a fresh, vibrant texture. Serve this over steamed rice, noodles or mashed potatoes, and you have a comforting and satisfying meal that’s as enjoyable to eat as it is to make.
Why You’ll Love This Slow Cooker Pepper Steak
Set it and forget it comfort food: The slow cooker does all the heavy lifting so the flavors can meld together while you do your own thing.
Tender, Juicy Beef: The long cooking time tenderizes the flank steak while it absorbs the sauce.
Perfect Balance of Sweet and Savory: Soy sauce and brown sugar make a savory-sweet sauce that coats the beef. Try our Chinese Beef and Onion Stir Fry next.
Bold And Texture Colors: Featuring the segment with bell peppers and also onions, this meal is as much an aesthetic pleasure as it is a flavor bomb.
Flexible Serving Options: Serve the beef and peppers over rice, noodles or mashed potatoes.
Key Ingredients
Bell Peppers
Color: Use a mix of red, yellow, and green bell peppers for color and flavor differences; from sweet to more earthy.
Freshness Counts: Choose firm, shiny bell peppers, so that they have a bit of chew when cooked. They’ll soften through the cooking time, but won’t turn mushy.
Substitutes: For a little heat, toss in a sliced poblano or two or a few thin slices of jalapeño with the bell peppers.
Onions
Sweet and Savory Notes: Yellow onions work best here for their mild sweetness that doesn’t overpower the sauce, but red or white onions will suffice, too. If you like this, you'll love our Mongolian Beef Stir-Fry with Ramen.
Slicing Thinly: Thinly sliced onions soften evenly in the sauce during slow cooking.
Cornstarch
Thickener: Coating the beef with cornstarch helps to thicken the sauce, but also gives the steak a silky texture.
Gluten-Free Substitute: Cornstarch is gluten-free by nature, though you can also use arrowroot powder or potato starch.
Soy Sauce and Brown Sugar
Sweet and Savory Base: Soy sauce equals a salty, umami base, and brown sugar brings a little sweetness to the party to balance it out. Combined, they form a sauce that enhances the beef magnificently.
Lower Sodium: Use low-sodium soy sauce, and adjust the brown sugar to taste.
Please see the recipe card down the page for a full list of ingredients with quantities and instructions
How to Make Slow Cooker Pepper Steak
Step 1: Preparing the Flank Steak
Slice the Steak:
Start by slicing 3 pounds of flank steak into thin strips across the grain. If the steak is hard to slice, chill it in the freezer until just firm, about 30 minutes.
Coat the Beef:
You will want to put the sliced flank steak in a large ziplock bag then add ½ cup of cornstarch on top. Seal the bag and shake to coat all the beef strips evenly. This will continue to thicken the sauce as the beef cooks.
Step 2: Prep the Slow Cooker Mixture
Combine Sauce Ingredients:
Combine 3 tablespoons olive oil, 1 cup brown sugar, 1½ cups soy sauce, 1½ cups water and 2 garlic cloves, minced in your slow cooker. Mix well to dissolve the sugar.
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Add the Beef:
Add the coated beef strips to the slow cooker, distributing them throughout the sauce mixture to allow the sauce to envelop each piece and ensure maximum flavor absorption. For another easy option, see our Shrimp & Teriyaki Steak Noodles.
Step 3: Cook the Beef
Set the Slow Cooker:
Put the lid on the slow cooker and cook on low for about 6 hours. Avoid opening the lid often, because this will let out heat and delay cooking time.
Step 4: Add Vegetables
Prepare the Vegetables:
About 1½ hours before the cooking time is up, slice 4 mixed-color bell peppers and 2 onions into thin strips.
Place Vegetables in Slow Cooker:
Stir the sliced bell peppers and onions into the slow cooker. Cover again and cook for another 90 minutes, long enough for the vegetables to soften but not mushy.
Step 5: Serve and Enjoy
Check for Doneness:
When it’s time to serve, it should be fork-shreddable, the beef tender and the vegetables tender-crisp.
Serve:
Serve the pepper steak spooned over a mound of steamed rice, noodles or — as a real treat — mashed potatoes. The sauce is rich and flavorful and it goes great with rice or potatoes, you can enjoy every bite.
Serving Suggestions
This Slow Cooker Pepper Steak makes a wonderful meal served with a variety of sides. Here are a couple of ideas for extending your meal:
Steamed White or Brown Rice: To soak up the savory sauce with.
Egg noodles or udon noodles that will soak up the sauce for an extra hit of flavor in every mouthful. And if you’re in the mood for comfort food, serve the pepper steak atop a mound of creamy mashed potatoes — warm, hearty and filling.
For something a bit lighter with an extra nutrition boost, stir in steamed vegetables such as broccoli florets, crisp green beans or sweet snap peas.
Finish the dish with optional garnishes such as sliced fresh green onions and toasted sesame seeds for added crunch and flavor.
Storage and Meal Prep
Slow Cooker Pepper Steak is one of those perfectly delicious meals that make fantastic leftovers. Here’s how to save it and heat it up:
Storage: Store leftovers in an airtight container in the refrigerator for up to 3–4 days. The flavors will develop and become even better after a day or two.
Freezing: This dish is freezer-friendly! Transfer cooled pepper steak to freezer container, freeze up to 2 months. Thaw in the refrigerator overnight, then reheat.
To Reheat: Reheat in a pan over low heat, occasionally stirring, until warmed through. If necessary, splash in water or broth to loosen the sauce. You might also like our Garlic Butter Steak Bites and Cheesy Smashed Potatoes.
Meal Prep Tip: Prep all the ingredients the night before and just dump everything into the slow cooker in the morning. So there this is an awesome resolution for busy week days!
Variations
So easy to customize to your taste as well in this Slow Cooker Pepper Steak! So for inspiration here are a few ideas:
Give It Heat: Spice lovers may want to add red pepper flakes or chopped jalapeños.
Asian-Inflected: Add 1 to 2 teaspoons of grated ginger and a tablespoon of sesame oil to the sauce for an Asian-flavored accent.
Low-Carb Option: Use cauliflower rice instead of rice, or serve over steamed vegetables for low-carb eaters.
More Veggies: You can also add other vegetables, like snap peas, zucchini or carrots, in the final hour of cooking for added texture and flavor.
Pineapple Pepper Steak: For sweet-savory version, stir 1 cup pineapple chunks into slow cooker during last 30 minutes of cooking time. Try our 4-Ingredient Slow Cooker Beef Cubed Steaks next.
More About This Pepper Steak
This slow cooker pepper steak recipe is one you’re gonna wanna add to your meal rotation with ease and flavor all in one dish! Tender, flavorful beef in a spicy sauce with lots of pepper make for a dinner that’s just as good for snuggling with family as it is for meal prep. With those tips and variations, you’ll have a pepper steak that’s truly toothsome. Enjoy! If you like this, you'll love our Savory Steak Gorgonzola Alfredo with Creamy Parmesan Sauce.
Slow Cooker Pepper Steak
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Ingredients
- 3 pounds flank steak sliced into thin strips
- 4 bell peppers sliced, mixed colors
- 2 onions sliced
- 3 tbsp olive oil
- 2 cloves garlic minced
- 1 1/2 cups soy sauce
- 1 1/2 cups water
- 1/2 cup corn starch
- 1 cup brown sugar packed
Instructions
- Slice 3 pounds of flank steak into thin strips across the grain. Place the steak in a zip-top bag with 1/2 cup cornstarch, seal, and shake until evenly coated.
- In the slow cooker, combine 3 tablespoons olive oil, 1 cup brown sugar, 1 1/2 cups soy sauce, 1 1/2 cups water, and 2 minced garlic cloves. Stir until sugar dissolves. Add the coated beef strips and spread evenly in the sauce.
- Cover and set the slow cooker on low for approximately 6 hours. Avoid lifting the lid frequently to retain heat.
- About 1 1/2 hours before the end, slice 4 bell peppers and 2 onions into thin strips. Add them to the slow cooker, cover again, and cook for the remaining time.
- Once done, serve the pepper steak over steamed rice, noodles, or mashed potatoes. Enjoy the flavorful sauce and tender beef!
Notes
Nutrition
Nutrition values are estimates based on the listed ingredients and serving count. Actual values vary with brands, cuts and portion sizes.
