This keto beef and broccoli stir-fry is ready in about 30 minutes, all in one pan. Tender strips of beef and crisp-tender broccoli are tossed in a glossy, savoury sauce that is naturally low in carbohydrates.
Why this keto beef and broccoli stir-fry works
- One pan for both the beef and the broccoli keeps washing-up to a minimum.
- A short soy and sesame marinade tenderises the beef in the time it takes to prep the vegetables.
- Xanthan gum thickens the sauce without the carbs of a cornflour slurry.
- Ready in about 30 minutes, making it realistic for a weeknight dinner.
This one fills a gap in our keto and low-carb and one-pot meals collections. If you liked our creamy garlic Parmesan chicken and broccoli, this is a beef-based way to get a similar low-carb dinner on the table.
Recipe details
- Serves: 4
- Preparation: 15 minutes
- Cooking: 15 minutes
- Total time: About 30 minutes
Ingredients
For the beef and marinade
- 500 g flank or sirloin steak, thinly sliced against the grain
- 2 tablespoons soy sauce or tamari
- 1 tablespoon sesame oil
- 2 cloves garlic, minced
- 1 teaspoon grated fresh ginger
For the stir-fry
- 2 tablespoons avocado oil or another neutral oil, divided
- 400 g broccoli florets
- 60 ml water, for steaming
For the sauce
- 60 ml soy sauce or tamari
- 120 ml beef stock
- 1 tablespoon rice vinegar
- 1 tablespoon granulated low-carb sweetener (optional)
- ½ teaspoon xanthan gum
- ½ teaspoon toasted sesame oil
- Sesame seeds and sliced spring onion, to finish
How to make keto beef and broccoli stir-fry
1. Marinate the beef
Combine the sliced steak with the soy sauce, sesame oil, garlic and ginger in a bowl. Toss to coat and leave for at least 10 minutes while you prepare the vegetables.
2. Steam the broccoli
Heat 1 tablespoon of oil in a large pan or wok over medium-high heat. Add the broccoli and water, cover, and steam for 2 to 3 minutes until just crisp-tender. Remove the broccoli and set aside.
3. Sear the beef
Wipe out the pan, add the remaining oil and increase the heat to high. Add the beef in a single layer, working in batches if needed, and sear for 1 to 2 minutes per side until browned. Remove and set aside with the broccoli.
4. Make the sauce
Whisk the soy sauce, beef stock, rice vinegar and sweetener (if using) in a small bowl. Whisk in the xanthan gum a little at a time to avoid clumps.
5. Combine and finish
Pour the sauce into the hot pan and bring to a simmer, stirring, until it thickens slightly, about 1 minute. Return the beef and broccoli to the pan and toss to coat. Stir in the sesame oil. Sprinkle with sesame seeds and spring onion and serve immediately, on its own or over cauliflower rice.
Tips for the best texture
- Slice the beef thinly and against the grain so it stays tender rather than chewy.
- Cook the beef in a single layer and avoid crowding the pan, or it will steam instead of sear.
- Add the xanthan gum gradually while whisking, as too much at once can make the sauce gluey.
- Keep the broccoli slightly crisp; it will continue to soften once tossed back into the hot sauce.
Variations
- Spicy: add ½ to 1 teaspoon chilli flakes or a spoonful of chilli garlic sauce to the marinade.
- Mushroom swap: replace half the beef with sliced mushrooms for a lighter version.
- Extra vegetables: add sliced peppers or mangetout with the broccoli.
- Nut-free sesame swap: use avocado oil in place of sesame oil if needed.
Storage and reheating
Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in a pan or the microwave until piping hot. The broccoli will soften further on reheating, so slightly undercook it if you plan to store leftovers.
Frequently asked questions
How many net carbs does this recipe have?
Using soy sauce, beef stock and a low-carb sweetener keeps the carbohydrate content low, largely from the broccoli itself. Net carbs (total carbohydrates minus fibre) are a common way keto recipes are compared, though it’s worth knowing that the FDA and American Diabetes Association do not officially recognise net carbs as a labelling term, so treat it as a helpful estimate rather than an exact figure.
Can I use frozen broccoli?
Yes. Thaw and pat it dry first, as frozen broccoli releases extra water that can make the sauce thinner than expected.
What if I don’t have xanthan gum?
You can simmer the sauce for a minute or two longer to reduce and thicken it naturally, though it will not be as glossy. Cornflour (cornstarch) will also work if you are not keeping the dish strictly low-carb.
What is the best cut of beef for stir-fry?
Flank, sirloin or skirt steak all work well because they are tender when sliced thinly against the grain and cooked quickly over high heat.
Can I make this ahead?
The beef can be sliced and marinated up to a day ahead and kept covered in the refrigerator. Cook the dish just before serving for the best texture.
For more low-carb dinners, see our keto and low-carb recipes.