Beef and broccoli stir-fry is a keto classic for good reason. This high-protein keto recipe delivers approximately 35 grams of protein per serving while keeping net carbs in single digits. The dish comes together in under 25 minutes, making it practical for weeknight dinners when you need something satisfying without the carb-heavy sauces found in takeaway versions.
Traditional beef and broccoli from Chinese restaurants typically contains sugar-laden sauces and cornstarch thickeners. This keto-friendly version swaps those ingredients for low-carb alternatives without sacrificing the savoury, umami-rich flavour profile you expect.
Why This Recipe Works for Keto
The ketogenic diet requires keeping daily carbohydrates between 20-50 grams to maintain ketosis. This beef and broccoli stir-fry fits comfortably within those parameters, providing just 6 grams of net carbs per generous serving.
Flank steak serves as the protein foundation. It's lean enough to keep calories reasonable while delivering the amino acids your muscles need for recovery and maintenance. Broccoli adds fibre, vitamin C, and volume to the meal without spiking your carb count.
The sauce uses coconut aminos or tamari instead of regular soy sauce (which can contain hidden sugars), and xanthan gum replaces cornstarch as the thickening agent. Both substitutions maintain the glossy, clingy sauce texture while keeping the recipe firmly in keto territory.
Ingredients
This recipe yields 4 servings. Each serving provides approximately 35 grams of protein.
For the Beef
- 680g (1.5 lbs) flank steak, thinly sliced against the grain
- 2 tablespoons avocado oil
- ½ teaspoon salt
- ¼ teaspoon black pepper
For the Broccoli
- 450g (4 cups) broccoli florets, fresh or frozen
- 1 tablespoon avocado oil
- 3 tablespoons water
For the Sauce
- 80ml (⅓ cup) coconut aminos or tamari
- 60ml (¼ cup) beef bone broth
- 2 tablespoons sugar-free sweetener (monk fruit or erythritol blend)
- 1 tablespoon sesame oil
- 3 garlic cloves, minced
- 1 teaspoon fresh ginger, minced or grated
- ½ teaspoon xanthan gum
- ½ teaspoon warm water
Optional Garnish
- 1 tablespoon sesame seeds
- 2 spring onions, thinly sliced
- Red pepper flakes
Step-by-Step Instructions
Step 1: Prepare the Sauce
Whisk together the coconut aminos, beef broth, sweetener, sesame oil, garlic, and ginger in a small bowl. Set aside.
In a separate tiny bowl, combine the xanthan gum with warm water. Stir vigorously until it forms a thick paste. This prevents clumping when you add it to the sauce later.
Step 2: Slice the Beef
Cut the flank steak against the grain into thin strips, approximately 5mm thick. Cutting against the grain shortens the muscle fibres and results in more tender pieces.
Pat the beef strips dry with paper towels. Excess moisture prevents proper browning and causes the meat to steam instead of sear.
Season the strips with salt and pepper.
Step 3: Sear the Beef
Heat 2 tablespoons of avocado oil in a large skillet or wok over high heat. Wait until the oil shimmers and just begins to smoke.
Add the beef strips in a single layer. Work in batches if necessary to avoid overcrowding. Overcrowded pans drop in temperature and cause steaming rather than searing.
Cook for 2 minutes without moving the beef to develop a brown crust. Flip and cook for another 1-2 minutes until browned on the second side but still slightly pink in the centre.
Transfer the beef to a plate and set aside. The residual heat will continue cooking it while you prepare the broccoli.
Step 4: Cook the Broccoli
Reduce heat to medium-high. Add 1 tablespoon of avocado oil to the same pan.
Add the broccoli florets and stir-fry for 2-3 minutes until bright green with some charred spots.
Add the 3 tablespoons of water to the pan and immediately cover with a lid. Steam for 2 minutes until the broccoli is tender-crisp.
Remove the lid and let any remaining water evaporate. Transfer the broccoli to the plate with the beef.
Step 5: Build the Sauce
With the pan still over medium-high heat, pour in the prepared sauce mixture. Bring to a simmer.
Add the xanthan gum paste to the simmering sauce while whisking constantly. The sauce will thicken within 30-60 seconds.
Step 6: Combine and Serve
Return the beef and broccoli to the pan. Toss everything together until evenly coated with the glossy sauce.
Simmer for 1-2 minutes to allow the flavours to meld and the sauce to cling to all the ingredients.
Serve immediately over cauliflower rice if desired. Garnish with sesame seeds, spring onions, and red pepper flakes.
Detailed Nutritional Breakdown
Each serving (approximately 250g) contains:
| Nutrient | Amount |
|---|---|
| Calories | 385 kcal |
| Protein | 35g |
| Total Fat | 22g |
| Saturated Fat | 6g |
| Total Carbohydrates | 9g |
| Dietary Fibre | 3g |
| Net Carbs | 6g |
| Sodium | 680mg |
Macronutrient Ratio
- Protein: 36%
- Fat: 51%
- Carbohydrates: 13%
This macro distribution aligns well with standard keto guidelines, which typically recommend 70-75% fat, 20-25% protein, and 5-10% carbohydrates. The slightly higher protein percentage makes this recipe particularly suitable for those following a high-protein keto approach or anyone prioritising muscle maintenance.
Tips for Success
Choose the right cut. Flank steak works best for stir-frying because it's lean, flavourful, and becomes tender when sliced thin against the grain. Skirt steak or sirloin make acceptable substitutes.
Slice while partially frozen. Place the steak in the freezer for 20-30 minutes before slicing. The firmer texture makes cutting thin, even strips much easier.
Maximise browning. High heat and dry beef are essential. Crowding the pan or using wet meat results in grey, steamed beef instead of the caramelised exterior you want.
Adjust thickness preference. If you prefer softer broccoli, steam for an additional minute. For extra crunch, reduce steaming time to 1 minute.
Storage and Meal Prep
This beef and broccoli keto recipe stores well, making it excellent for meal prep.
Refrigerator: Store in airtight containers for up to 4 days. The sauce may thicken slightly when cold but loosens when reheated.
Freezer: Freeze for up to 3 months. Thaw overnight in the refrigerator before reheating.
Reheating: Use a skillet over medium heat for best results. Microwave works but may result in slightly softer broccoli texture. Add a splash of beef broth if the sauce has become too thick.
Electrolyte Considerations on Keto
The ketogenic diet causes your body to excrete more sodium, potassium, and magnesium than usual. This stir-fry provides a decent sodium content from the coconut aminos, but you may still need to supplement electrolytes, particularly during the first few weeks of keto.
Common signs of electrolyte imbalance include muscle cramps, headaches, fatigue, and dizziness: often called "keto flu." Fitness Health electrolyte supplements can help maintain proper mineral balance and support your transition into ketosis.
Variations and Modifications
Lower sodium version: Use reduced-sodium tamari and cut the amount to 60ml. Add an extra tablespoon of beef broth to maintain sauce volume.
Spicier version: Add 1 teaspoon of chilli paste or ½ teaspoon of crushed red pepper flakes to the sauce.
Different vegetables: Swap half the broccoli for bok choy, mushrooms, or snap peas. Adjust net carbs accordingly if using higher-carb vegetables.
Dairy-free confirmation: This recipe is naturally dairy-free, making it suitable for those following both keto and dairy-free protocols.
Key Takeaways
This keto beef and broccoli stir-fry delivers 35 grams of protein per serving with only 6 grams of net carbs. The recipe takes under 25 minutes from start to finish, stores well for meal prep, and provides the satisfying umami flavours of restaurant versions without the hidden sugars and starches.
For more high-protein meal ideas that support your fitness goals, check out our quick and easy high-protein breakfast recipes to round out your daily protein intake.
