Slow Cooker Kung Pao Beef
Slow Cooker Kung Pao Beef is a bold, sweet, savory, and slightly spicy dinner made with tender beef, bell peppers, garlic, soy sauce, brown sugar, hoisin, and roasted peanuts. It is cozy, colorful, and perfect served over rice or noodles.
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Ingredients
- 2 pounds flank steak or sirloin steak sliced into thin strips
- 1 teaspoon salt
- 1 teaspoon pepper
- 2 tablespoons cornstarch
- 1 tablespoon oil
- 1 red bell pepper chopped into chunks
- 1 green bell pepper chopped into chunks
- 1 small onion chopped into chunks
- ½ cup low sodium soy sauce
- ¼ cup beef broth
- ¼ cup brown sugar
- 2 tablespoons hoisin sauce
- 1 tablespoon rice vinegar
- 1 tablespoon sesame oil
- 1 tablespoon minced garlic
- 1 teaspoon ground ginger
- 1 –2 teaspoons crushed red pepper flakes
- 2 tablespoons cornstarch
- 3 tablespoons water
- ½ cup roasted peanuts
- Sliced green onions and sesame seeds for garnish optional
Instructions
- Step 1: Season the Beef - Add the sliced beef to a large bowl, then sprinkle it with the salt and pepper. Use your hands or a sturdy spoon to toss it around until the seasoning is spread over the strips. I like to do this before anything else because beef needs a little attention right at the start. It is just like teaching kids to tie their shoes. A little patience early makes everything go smoother later.
- Step 2: Coat the Beef with Cornstarch - Sprinkle the first 2 tablespoons of cornstarch over the seasoned beef and toss until every strip has a light coating. This little step matters more than it looks like it should. The cornstarch helps the beef brown in the skillet and also helps the finished sauce cling to the meat. You do not want clumps here, just a light dusty coating.
- Step 3: Sear the Beef - Heat the oil in a large skillet over medium high heat. Add the beef in batches so the pan does not get crowded. Let it sear for 1 to 2 minutes, just until lightly browned. You are not cooking it all the way through here. You are just building flavor. If you pile all the beef in at once, it will steam instead of brown, and we want that little bit of color.
- Step 4: Add the Beef to the Slow Cooker - Transfer the seared beef to the slow cooker. Try to scrape in any tasty browned bits from the skillet too, because that is flavor you already paid for. Spread the beef out a bit so the sauce can work its way around it. This is where dinner starts to feel easy.
- Step 5: Add the Vegetables - Add the red bell pepper, green bell pepper, and onion over the beef. If your family likes softer vegetables, add them now and let them cook the whole time. If you like your peppers with more bite, add them during the last 1 to 2 hours instead. I usually add them at the start because I like how they melt into the sauce, but both ways work.
- Step 6: Whisk the Sauce - In a medium bowl, whisk together the soy sauce, beef broth, brown sugar, hoisin sauce, rice vinegar, sesame oil, minced garlic, ground ginger, and crushed red pepper flakes. Give it a good whisk until the brown sugar starts to dissolve. This sauce should smell bold, sweet, savory, and a little spicy. That is how you know you are heading in the right direction.
- Step 7: Pour and Slow Cook - Pour the sauce evenly over the beef and vegetables. Cover the slow cooker and cook on low for 4 to 6 hours or on high for 2 to 3 hours, until the beef is tender. I prefer low when I have the time because the beef gets softer and the flavors settle in better. Still, high works just fine when dinner needs to happen sooner.
- Step 8: Thicken the Sauce - In a small bowl, whisk the remaining 2 tablespoons cornstarch with 3 tablespoons water until smooth. Stir this slurry into the slow cooker gently so you do not break up the beef too much. Cover and cook on high for another 10 to 15 minutes. The sauce will thicken and turn glossy, which is exactly what you want.
- Step 9: Finish with Peanuts and Garnish - Stir in the roasted peanuts right before serving so they keep some crunch. Sprinkle with sliced green onions and sesame seeds if you are using them. Serve warm over white rice or noodles, and make sure to spoon plenty of that sauce over the top. That sauce is the whole point, and nobody should miss out on it.
Notes
Substitutions
- Chicken instead of beef: Thin sliced chicken thighs or chicken breast can be used if you want a lighter version.
- Coconut aminos instead of soy sauce: This works well if you need a soy free option, though the flavor will be a little sweeter.
- Cashews instead of peanuts: Cashews give a buttery crunch and are a great swap.
- Yellow or orange bell peppers: These add more sweetness and make the dish even more colorful.
- Fresh ginger instead of ground ginger: Use about 1 tablespoon fresh grated ginger for a brighter flavor.
Variations
- Extra spicy: Add more crushed red pepper flakes or a spoonful of chili garlic sauce.
- Veggie loaded: Add broccoli, snap peas, carrots, or mushrooms during the last part of cooking.
- Sweeter sauce: Add a little extra brown sugar or a drizzle of honey.
- Garlic lover version: Double the garlic for a bolder sauce.
- Takeout bowl: Serve with fried rice, egg rolls, and extra green onions on top.
Tips and Tricks
- Slice the beef thin: Thin strips cook more evenly and turn tender faster.
- Do not skip the sear: Browning the beef adds flavor that the slow cooker cannot create by itself.
- Add vegetables later for crunch: Put peppers and onions in during the last 1 to 2 hours if you want them crisp tender.
- Use fresh garlic when possible: It gives the sauce a stronger, fresher flavor.
- Let the sauce thicken fully: Give the slurry time to work so the sauce becomes shiny and rich.
Serving Ideas
- White rice: A warm scoop of rice is perfect for catching all that glossy sauce.
- Noodles: Serve the beef over lo mein noodles, rice noodles, or even spaghetti in a pinch.
- Steamed broccoli: The bright green color and simple flavor balance the rich sauce.
- Fried rice: This makes the meal feel like a full takeout night at home.
- Egg rolls: Add a crispy side and dinner feels extra fun.
Storage and Make Ahead Tips
- Refrigerator storage: Store leftovers in an airtight container in the refrigerator for up to 3 days.
- Freezer storage: Freeze in a sealed container for up to 2 months, then thaw overnight in the refrigerator.
- Reheating on the stove: Warm gently in a skillet over medium heat, adding a splash of broth or water if the sauce is too thick.
- Reheating in the microwave: Heat in short bursts and stir between each one so the beef warms evenly.
- Make ahead sauce: Whisk the sauce ingredients together a day ahead and keep it covered in the refrigerator.
Private Notes
Servings: 6 servings
