This Slow Cooker Pepper Steak combines tender strips of flank steak with colorful bell peppers and onions, all simmered in a rich, savory-sweet sauce made with soy, brown sugar, and garlic. The slow-cooked beef absorbs the flavorful sauce, becoming melt-in-your-mouth tender, while the bell peppers and onions retain a fresh, vibrant texture. Serve over steamed rice, noodles, or mashed potatoes for a comforting and satisfying meal that’s as easy as it is delicious.

Why You’ll Love This Slow Cooker Pepper Steak:

Effortless Comfort Food: The slow cooker does all the work, allowing the flavors to meld together while you go about your day.
Tender, Juicy Beef: The long, slow cooking time tenderizes the flank steak to perfection, making each bite succulent and flavorful.
Perfect Balance of Savory and Sweet: The soy sauce and brown sugar blend create a delightful sauce that brings out the richness of the beef.
Vibrant Colors and Textures: With a mix of bell peppers and onions, this dish not only tastes amazing but also looks as good as it tastes.
Family-Friendly: With its mild sweetness and tender beef, this dish is a crowd-pleaser that even picky eaters enjoy.

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Key Ingredients:

1. Flank Steak

Perfect Cut for Slow Cooking: Flank steak becomes incredibly tender with slow cooking. It’s flavorful and pairs wonderfully with the sauce.
Thin Slicing: For best results, slice the steak against the grain to keep it tender and easy to eat. If slicing is tricky, freeze the steak for 20-30 minutes to make it easier to handle.
Alternative Cuts: If you prefer, you can use sirloin, chuck roast, or skirt steak, which also work well in the slow cooker.

2. Bell Peppers

Colorful Variety: Use a mix of red, yellow, and green bell peppers for a vibrant look and a range of flavors, from mildly sweet to earthy.
Freshness Matters: Choose firm, glossy bell peppers to ensure they retain some bite after cooking. They’ll soften during the cooking time without becoming mushy.
Substitutes: If you want a bit of heat, add in a sliced poblano or a few thin slices of jalapeño alongside the bell peppers.

3. Onions

Sweet and Savory Notes: Yellow onions are ideal here for their mild sweetness that complements the sauce, but red or white onions work just as well.
Slicing Thinly: Thinly sliced onions cook quickly and melt into the sauce, adding depth and complexity to the flavor profile.

4. Cornstarch

Thickening Agent: Coating the beef in cornstarch not only helps thicken the sauce but also gives the steak a velvety texture.
Gluten-Free Substitute: Cornstarch is naturally gluten-free, but arrowroot powder or potato starch can also be used if you prefer.

5. Soy Sauce and Brown Sugar

Sweet and Savory Base: Soy sauce provides a salty, umami base, while brown sugar balances with a slight sweetness. Together, they create a delicious sauce that brings out the best in the beef.
Low-Sodium Option: To reduce salt, choose a low-sodium soy sauce and adjust the brown sugar to taste.

Complete list of ingredients with quantities and instructions is located in the recipe card below

Instructions:

Step 1: Prepare the Flank Steak

Slice the Steak:
Begin by slicing 3 pounds of flank steak into thin strips. If the steak is difficult to slice, partially freeze it for about 30 minutes to make it easier.

Coat the Beef:
Place the sliced flank steak into a large ziplock bag and add ½ cup of cornstarch. Seal the bag and shake until all the beef strips are evenly coated. This will help thicken the sauce as the beef cooks.

Step 2: Prepare the Slow Cooker Mixture

Combine Sauce Ingredients:
In your slow cooker, mix together 3 tablespoons of olive oil, 1 cup of brown sugar, 1½ cups of soy sauce, 1½ cups of water, and 2 minced garlic cloves. Stir well until the sugar dissolves.

Add the Beef:
Place the coated beef strips into the slow cooker, spreading them out evenly in the sauce mixture to ensure each piece is submerged for maximum flavor absorption.

Step 3: Cook the Beef

Set the Slow Cooker:
Cover the slow cooker and set it to cook on low for approximately 6 hours. Avoid lifting the lid frequently, as this will release heat and extend cooking time.

Step 4: Add Vegetables

Prepare the Vegetables:
About 1½ hours before the cooking time is up, prepare 4 bell peppers (mixed colors for visual appeal) and 2 onions. Slice the bell peppers and onions thinly.

Add Vegetables to the Slow Cooker:
Stir the sliced bell peppers and onions into the slow cooker. Re-cover and continue cooking for the remaining 90 minutes, allowing the vegetables to soften without becoming mushy.

Step 5: Serve and Enjoy

Check for Doneness:
Before serving, check that the beef is tender and easily shredded with a fork, and that the vegetables are tender-crisp.

Serve:
Spoon the pepper steak over a bed of steamed rice, noodles, or mashed potatoes. The rich, flavorful sauce pairs perfectly with rice or potatoes, making each bite satisfying.

Serving Suggestions:

This Slow Cooker Pepper Steak pairs beautifully with a variety of sides. Here are a few ideas to round out your meal:

Steamed White or Brown Rice: Perfect for soaking up the savory sauce.
Egg Noodles or Udon: A fantastic alternative to rice, these noodles are a delicious way to enjoy the sauce.
Mashed Potatoes: For a comforting option, serve the pepper steak over creamy mashed potatoes.
Steamed Vegetables: Add a side of broccoli, green beans, or snap peas for extra color and nutrients.
Garnishes: Sprinkle with sliced green onions or toasted sesame seeds for added texture and flavor.

Storage and Meal Prep Tips:

Slow Cooker Pepper Steak makes for fantastic leftovers. Here’s how to store and reheat it:

Refrigeration: Store leftovers in an airtight container in the fridge for up to 3-4 days. The flavors will continue to meld and even improve after a day or two.
Freezing: This dish freezes well! Place cooled pepper steak in a freezer-safe container and freeze for up to 2 months. Thaw overnight in the fridge before reheating.
Reheating: Reheat on the stove over low heat, stirring occasionally, until warmed through. Add a splash of water or broth to loosen the sauce if needed.
Meal Prep Idea: Prep all the ingredients the night before, then simply add them to the slow cooker in the morning. This is a great solution for busy weekdays!

Variations to Try:

This Slow Cooker Pepper Steak is easy to customize to suit your tastes. Here are a few ideas to inspire you:

Add Heat: For a spicy kick, add red pepper flakes or sliced jalapeños to the sauce.
Asian-Inspired: Incorporate 1-2 teaspoons of grated ginger and a tablespoon of sesame oil to the sauce for a more Asian-inspired flavor.
Low-Carb Option: Swap out the rice or noodles for cauliflower rice or serve over steamed vegetables for a low-carb meal.
Extra Veggies: Feel free to add additional vegetables like snap peas, zucchini, or carrots in the last hour of cooking for more texture and flavor.
Pineapple Pepper Steak: For a sweet and savory twist, add a cup of pineapple chunks to the slow cooker in the last 30 minutes of cooking.

Conclusion:

This Slow Cooker Pepper Steak recipe combines ease and flavor into one dish that’s sure to become a regular in your meal rotation. Perfectly tender beef, a flavorful sauce, and colorful peppers create a meal that’s just as good for cozy family dinners as it is for meal prep. Follow these tips and variations, and you’ll have a pepper steak that’s truly mouthwatering. Enjoy!