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Slow Cooker Korean Beef with Sweet Baby Peppers

Slow Cooker Korean Beef with Sweet Peppers uses flank steak and sweet peppers to create a fresh meal using your slow cooker that’s simple and quick to make!

closeup of slow cooker korean beef

What is Korean Beef?

Why should I make Korean Beef with Baby Sweet Peppers? For starters, it’s really quick to prep (only 15 minutes!). Also, it’s full of flavors even the kids will like. Plus, this recipe is packed with protein and veggies, making it a healthy choice if you’re serving someone who’s counting calories and carbs.

ingredients for slow cooker korean beef


Which cut of meat is best for Korean Beef in the slow cooker? Some recipes use beef tongue or other cuts of beef. However, the thin slices of beef flank steak used in this recipe cook up perfectly.

What are baby sweet peppers? Baby sweet peppers (sometimes called “mini peppers”) are simply smaller versions of the bell peppers that you’re familiar with. They’re sweeter than a bell pepper. They’re crunchier than a bell pepper. And, they’re undeniably more convenient than bell peppers to prep and use in a recipe such as this.

Can I use regular vinegar in stead of rice vinegar? Rice vinegar and white vinegar are not the same things. Rice vinegar is rather sweet and will add that flavor to whatever you’re cooking. White vinegar has a stronger flavor and is definitely not sweet. (It’s the one people sometimes use as a household cleaner.) You don’t want white vinegar’s sourness messing up the flavor of your Korean Beef.

sauce poured on beef flank steak in slow cooker


What’s the best way to prep the flank steak for Korean Beef? Your flank steak needs to be sliced thin to cook up properly–about 1/4 inch think. If your meat is a bit frozen, it will slice easier.

Do I need to remove seeds from the peppers? Yes! Most mini peppers have few to no seeds. But, they might have some and you’ll need to get them out before slicing. The easiest way to do this is to chop off the ends and then stand the pepper upright. Get your knife inside and slice the seeds off.

For a gluten free option, substitute Tamari for soy sauce. For a corn free option, substitute tapioca flour for cornstarch.

steak and peppers in slow cooker

Serving Suggestions…

What can I serve Slow Cooker Korean Beef with? You can’t go wrong serving this Korean Beef over a bed of rice. Some of my favorites can be made in the Instant Pot or the traditional way (stove top) : Basmati Rice, Brown Rice, Jasmine Rice, and Fried Rice.

Leftovers can be stored in an airtight container for up to 3 days. I don’t recommend freezing this recipe.

overhead shot of korean beef in slow cooker and bowl
overhead shot of korean beef in bowl with napkin

closeup of slow cooker korean beef

Slow Cooker Korean Beef with Sweet Baby Peppers

Jennifer Draper
Slow Cooker Korean Beef with Sweet Peppers uses flank steak and sweet peppers to create a fresh meal using your slow cooker that's simple and quick to make!
4.36 from 39 votes
Prep Time 15 minutes
Cook Time 6 hours
Total Time 6 hours 15 minutes
Course Main Course
Cuisine Korean
Servings 4
Calories 338 kcal


  • 1 1/2 pounds flank steak or so
  • 6-8 baby sweet peppers
  • 2 tablespoons corn starch
  • 1/2 cup soy sauce
  • 1/4 cup brown sugar
  • 1 teaspoon rice vinegar
  • 1/2 teaspoon chili garlic sauce
  • 1/2 teaspoon minced garlic
  • 1/2 teaspoon sesame oil
  • 1/4 teaspoon garlic powder
  • 1/4 teaspoon onion powder
  • 1/8 teaspoon black pepper


  • Slice flank steak thin, into about 1/4 inch strips. Place in crock.
  • Remove ribs and seeds from peppers and slice, set aside
  • Whisk cornstarch with 2-3 tablespoons of water until smooth
  • Mix together remaining ingredients in measuring cup or small bowl then mix in cornstarch slurry
  • Pour sauce over meat and top with peppers
  • Cover and cook on low for 6-8 hours
  • Serve over rice or with noodles as desired


  • flank steak is the best cut of meat to use for this recipe. If you leave it partially frozen, it will be easier to cut into thin strips
  • remove seeds from peppers for best results
  • for a gluten free option, use Tamari instead of soy sauce
  • for a corn free option, use tapioca flour instead of cornstarch


Calories: 338kcalCarbohydrates: 22gProtein: 40gFat: 9gSaturated Fat: 4gCholesterol: 102mgSodium: 1747mgPotassium: 748mgFiber: 1gSugar: 16gVitamin A: 1315IUVitamin C: 54mgCalcium: 56mgIron: 4mg
Tried this recipe?Mention @slowcookergourmet or tag #slowcookergourmet!
Important nutritional disclaimer



      1. (People who follow a carnivore diet eat only animal products. Rice and vegetables wouldn’t work for people following that diet.)

        1. Gotcha! I definitely don’t have recipes for specific diets here, so I’m not sure they came across the recipe, but hopefully they found something elsewhere that worked for them!

  1. 5 stars
    I made this in my multi pot (similar to an instant pot) it took 35 mins! Came out amazing my boyfriend and I loved it.

  2. 5 stars
    Hey there. So i use steak tips instead of flank steak that works well!! Also could i do the baby peppers whole? Just cut the ends? And finally any way to put a tasty bite in there. Spicy but not too spicy? Sriracha is not the answer. I need something with a full flavor but kid friendly!

    Thank u

    1. Yes, I think you could leave them whole. And if you want to add a little spice, I would add additional chili garlic sauce, some Sriracha, or add some red pepper flakes.

      1. You say to leave the peppers whole but in the recipe it says to slice the? Also you say in recipe to add sliced peppers in beginning but in this response you say to add later?

  3. 5 stars
    Hi! Just wondering how big the crockpot should be for this receipe. Still figuring things out, bought one last week (a 5.7L for 6-8 People) so i doubled the receipe. Should that be oké?

  4. This tastes good, but mine looks horrible. The peppers lost all of their color, and the sauce darkened a lot. Luckily, the sauce “shellacs” everything and is delicious. The beef is tender, too. Next time, I’ll hold back half of the peppers to add later.

  5. Hi Jennifer! I also buy meat that is marked down. In my supermarket, they mark down the meat on Thursdays, because the new sale starts on Friday. This might be true with your local store as well.

    1. Hi Fritz! They come in a bag that’s about 1 pound and are labeled sweet mini peppers. If you can’t find them at your supermarket, feel free to sub regular bell peppers.

4.36 from 39 votes (35 ratings without comment)

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