Mongolian crispy lamb is a British Chinese takeaway-style dish of thin lamb strips fried in a crisp cornflour coating, then tossed in a sweet-savoury garlic, ginger and hoisin sauce. It is not a traditional dish from Mongolia; this version is made for the crunchy texture and glossy sauce many UK diners expect, and it comes together quickly once the lamb is sliced.
Ingredients
- 1 lb (450 g) boneless lamb leg steaks, trimmed of excess fat and sliced into strips about ¼ inch (6 mm) thick
- ½ cup (64 g) cornflour, also called cornstarch, for coating
- ¼ tsp (1.5 g) fine salt, or less if your soy sauce is very salty
- ¼ tsp (0.5 g) ground black pepper
- ½ cup (120 ml) neutral oil, such as sunflower or rapeseed oil, for shallow-frying; you may not need every drop
- 3 tbsp (45 ml) light soy sauce
- 2 tbsp (30 g) hoisin sauce
- 2 tbsp (25 g) light brown sugar
- 1 tbsp (15 ml) rice vinegar
- 3 tbsp (45 ml) water, plus 1 tbsp (15 ml) cold water for the slurry
- 1 tsp (3 g) cornflour (cornstarch), for thickening the sauce
- 3 garlic cloves (about 15 g), finely grated or minced
- 1 tbsp (15 g) fresh ginger, peeled and finely grated
- 1 tsp (5 ml) toasted sesame oil
- ½ tsp (1 g) dried chilli flakes, or to taste
- 4 spring onions (about 60 g), thinly sliced, with the white and green parts separated
- 1 tsp (3 g) sesame seeds, to finish (optional)
Instructions
- Slice and dry the lamb. Pat the lamb steaks dry with kitchen paper, then cut across the grain into even strips around ¼ inch (6 mm) thick. Keeping the strips similar in size helps them cook at the same speed. If the steaks are very thick, slice them horizontally first. Trim away only large pieces of hard fat; a little marbling adds flavour.
- Mix the coating and sauce ingredients. In a shallow bowl, combine the ½ cup (64 g) cornflour with the salt and pepper. In a separate small bowl, stir together the soy sauce, hoisin, brown sugar, rice vinegar and 3 tbsp (45 ml) water. In another cup, mix the 1 tsp (3 g) cornflour with the remaining 1 tbsp (15 ml) cold water until smooth; keep this slurry nearby. Having these ready before frying means the lamb can go straight into the sauce while it is still crisp.
- Coat and rest the lamb. Toss the strips in the seasoned cornflour, separating them so each piece has a light, even coating. Shake off loose excess, then arrange the pieces on a plate or tray without piling them up. Leave them for 10 minutes. This brief rest lets the coating cling instead of falling into the pan, but do not leave raw lamb at room temperature longer than needed.
- Shallow-fry in batches. Pour enough neutral oil into a large, heavy frying pan or wok to cover the base by roughly ⅛ inch (3 mm), usually a few tablespoons. Heat over medium-high until a pinch of cornflour sizzles on contact, without letting the oil smoke. Add a single uncrowded layer of lamb; fry for about 2 minutes, turn the strips and cook for another 1–2 minutes, until golden and crisp. Transfer to a wire rack set over a tray. Repeat with the remaining lamb, adding a little oil if the pan looks dry. Crowding lowers the pan temperature and makes the coating soft, so use two or three batches rather than rushing.
- Check the lamb is safely cooked. Use a food thermometer to check the thickest lamb strips. USDA FSIS gives whole cuts of lamb a safe minimum internal temperature of 145°F (63°C), followed by a 3-minute rest. If a strip has not reached that temperature, return the batch to the pan briefly and check again. Rest the cooked lamb on the rack for 3 minutes while you make the sauce; the rack allows steam to escape and helps the coating stay crisp.
- Make the glossy sauce. Carefully pour away most of the frying oil, leaving about 1 tsp in the pan. Return it to medium heat and add the garlic, ginger and the white parts of the spring onions. Stir for about 30 seconds, just until fragrant; do not let the garlic brown. Pour in the soy-hoisin mixture and bring it to a gentle simmer. Stir the cornflour slurry again, then add it gradually, stirring constantly for 30–60 seconds until the sauce lightly coats the back of a spoon. If it gets too thick, loosen it with a splash of water.
- Toss and serve straight away. Turn off the heat and stir in the sesame oil and chilli flakes. Add the crisp lamb and toss quickly to coat; stop as soon as it is glossy so the coating does not sit in the sauce and soften. Scatter over the green spring onion tops and sesame seeds, if using, and serve immediately.
Tips
- Slice across the grain. Look for the direction of the long muscle fibres and cut across them. Thin strips cut this way are easier to bite and cook quickly. If the lamb is difficult to slice, chill it in the freezer for 15–20 minutes until firm but not frozen solid.
- Keep the coating light. Cornflour gives the lamb its delicate crisp shell. Shake off extra powder, and avoid adding wet lamb to the bowl. If using frozen lamb, thaw it safely in the refrigerator and pat it very dry before coating.
- Use a practical hoisin substitute if needed. Hoisin gives the sauce its thick, sweet, savoury character. If unavailable, mix 1 tbsp (15 g) smooth peanut butter with 1 tbsp (15 ml) extra soy sauce and 1 tsp (5 ml) honey; the result is less complex and slightly nuttier, so taste before adding all the sugar.
- Control the heat and salt. Chilli flakes and soy sauces vary, so begin with the listed amounts and adjust the finished sauce. Use reduced-salt soy sauce if preferred, but do not omit the sauce tasting step. Keep the pan hot enough to sizzle, not smoking; burnt garlic or overheated oil can make the dish bitter.
Serving Suggestions
Serve the lamb as soon as it is tossed, while the coating still has some crunch. Steamed jasmine or long-grain rice is a simple match for the sticky sauce; egg-fried rice or plain noodles also work well. For a fresh contrast, add quick-cooked pak choi, tenderstem broccoli, sliced cucumber or a lightly dressed cabbage salad. Keep vegetables fairly plain because the lamb sauce is already punchy and sweet-savoury.
For a takeaway-style spread, offer extra sliced spring onion, sesame seeds and chilli oil at the table, with the chilli oil served separately so everyone can choose their own heat level. This recipe makes four main-course portions with rice, or six smaller portions as part of a shared meal. If serving buffet-style, keep the lamb hot and avoid leaving it at room temperature for more than two hours.
Variations
Make it hotter: Increase the chilli flakes to 1 tsp (2 g), or add finely sliced fresh red chilli to the pan with the garlic and ginger. Fresh chilli gives a brighter, sharper heat. For a milder version, leave the chilli out altogether.
Try another cut: Lamb leg steaks are convenient because they are lean and easy to slice. Boneless lamb rump also works, while shoulder can be more marbled and may need trimming. Keep the strips thin and use the thermometer guidance rather than relying only on colour. Beef steak can be substituted, although it changes the flavour and cooking time may differ with the cut and thickness.
Use a less sweet sauce: Reduce the brown sugar to 1 tbsp (12 g) and add an extra 1 tsp (5 ml) rice vinegar for a sharper finish. Hoisin itself is sweet, so taste the simmering sauce before adding more sugar. For a gluten-free adaptation, use certified gluten-free soy sauce or tamari and check the hoisin label; ordinary versions may contain wheat.
Change the cooking method: Shallow-frying gives the most reliable crisp coating. You can use a deep fryer according to its manufacturer’s directions, cooking in small batches and checking the lamb temperature. An air fryer is less predictable with a loose cornflour coating and usually needs a light oil spray; the result tends to be drier and less evenly crisp, so check early and avoid crowding the basket.
Storage and Reheating
For the best texture, serve this dish straight away. If you have leftovers, refrigerate them within 2 hours in a shallow, covered container. Cooked lamb keeps for 3–4 days in the refrigerator. The coating will soften as it sits in the sauce, so if you expect leftovers, consider storing any extra sauce separately and combining only the portions you plan to eat.
Reheat leftovers in a frying pan over medium heat with a teaspoon of water, stirring until steaming hot throughout; check with a food thermometer that the centre reaches 165°F (74°C). A microwave also works: cover loosely, heat in short bursts, stir between bursts and confirm the same temperature. The lamb will be safe and hot but will not be as crisp as freshly fried. Do not reheat it more than once. For longer storage, freeze promptly in a suitable container for up to 2 months for best quality, then thaw in the refrigerator and reheat to 165°F (74°C).
Frequently Asked Questions
Is Mongolian crispy lamb actually from Mongolia?
This recipe is a UK Chinese takeaway-style dish rather than a traditional Mongolian preparation. The name is used for a family of Western Chinese restaurant-style dishes, and recipes vary. This version focuses on crisp-fried lamb with a sweet, savoury sauce and spring onion.
Can I make the lamb crispy without deep-frying?
Yes. Shallow-frying in a thin layer of oil is the method here: turn the strips so both sides brown, and fry in batches. A crowded pan steams the coating instead of crisping it. Air frying is possible, but the result is usually less evenly crunchy, especially if the cornflour is not lightly oiled.
Why did my cornflour coating turn gummy?
Common causes are damp lamb, too much loose cornflour, an overcrowded pan or letting the coated pieces sit for a long time. Dry the meat well, shake off excess coating, leave it only for the stated 10-minute rest and fry in a single layer. Toss with sauce at the last moment rather than letting the cooked lamb simmer in it.
Can I prepare any part of the recipe ahead?
Mix the sauce ingredients and refrigerate them in a covered container for up to a day. You can also slice the lamb ahead and keep it covered in the refrigerator, then pat it dry and coat it shortly before frying. For the crispest result, do not fry the lamb in advance and leave it sitting in sauce.
What can I use instead of hoisin sauce?
A mixture of smooth peanut butter, extra soy sauce and a little honey is a useful stand-in, though it tastes nuttier and less aromatic than hoisin. Check labels for allergens and gluten if cooking for someone with dietary restrictions. Taste the sauce before thickening and adjust the sugar, vinegar or water to balance it.
Can I use lamb mince for this recipe?
Not as a direct swap. Mince cannot be cut into the crisp strips this recipe relies on, and ground meat needs a different method and a USDA FSIS safe minimum internal temperature of 160°F (71°C). For a similar flavour, cook mince separately until it reaches that temperature, then spoon the sauce over it; expect a saucy lamb dish rather than crispy lamb.
Related
- Mongolian Ground Beef Ramen Recipe
- Mongolian Beef Recipe: Sweet-Savory Takeout at Home
- Mongolian Beef Recipe with a Lighter Skillet Sauce
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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes
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