Proteins

Lamb Flap

Fatty cut from the lamb belly, popular grilled or boiled across the Pacific Islands.

Lamb flap, also called sip sip or mutton flap, is the fatty, layered cut from the belly of the lamb. It is a staple across the Pacific Islands and parts of the Caribbean, typically grilled over charcoal, braised, or boiled until tender, with its high fat content basting the meat as it cooks. Inexpensive and rich, it delivers a deeply savory, fatty flavor.

Lamb flap is the fatty, flavor-intensive cut from the lower rib and flank area of the lamb, distinct from boneless lamb belly in that it retains the rib bones and a thick fat cap in a single connected piece. This cut is a workhorse of Pacific Rim cooking, particularly cherished in Hawaii, New Zealand, and throughout Polynesian cuisine where it is often simply seasoned with garlic and black pepper, then grilled or boiled until the fat renders into the meat. The high fat content—35 to 45 percent by weight—makes lamb flap extraordinarily forgiving: it stays moist well past medium and the rendered fat can be saved for frying or enriching braising liquids. The collagen in the fat cap breaks down to soft, unctuous gelatin when cooked low-and-slow, giving the meat a silky texture, though quick high-heat methods will leave it chewy rather than tender. In Hawaiian kitchens, lamb flap appears in lau lau bundles wrapped in taro leaves, while New Zealand butchers have begun marketing it to American chefs under the traditional Hawaiian term. Ask your butcher by weight—this cut is frequently an add-on sale item and significantly underpriced for its eating quality and versatility.

Measured in: g
Storage: Fridge

Types & varieties

Bone-in lamb flap

Traditional cut; bone adds depth during braising and roasting; harder to slice evenly for service

Deboned lamb flap

Easier to portion and slice; preferred for grilling, stir-frying, and precise service pieces

Lamb Flap vs. Lamb Belly

These are not the same cut, though they come from the same general belly area. Lamb belly is the boneless, skinless abdominal meat stripped of bone and fat cap. Lamb flap retains the rib bones and the thick layer of fat that runs along one edge, which makes it far more forgiving in cooking and richer in flavor. When a recipe calls for one, substituting the other requires adjusting cooking method and time—belly needs more fat added or longer braising to match flap's richness.

Sourcing and Buying

Lamb flap is underutilized in most American markets and is often sold as an add-on item at discount pricing. Ask your butcher specifically for lamb flap by weight rather than waiting for it to appear on the regular counter. New Zealand and Australian lamb tends to have a milder flavor with cleaner fat; local lamb varies by region. Look for pieces with a uniform fat cap at least half an inch thick and avoid any that shows discoloration or dried edges, which indicate oxidation of the fat.

Ask for it by weight — it is frequently an add-on sale item
Request bone-in for braising, deboned for grilling or slicing
Look for a thick, even fat cap — at least 1/2 inch
Avoid pieces with dried or browned edges on the fat

Common uses

Grilled whole or in strips, Hawaiian-style with garlic, salt, and black pepperBraised or slow-cooked in aromatics until fork-tenderBoiled in salted water, then crisped in a hot pan for textural contrastRolled and tied as a roast, then sliced into medallionsChopped for terrines, stuffings, or kebab mixtures where the fat adds richnessUsed in lau lau — traditional Hawaiian taro-leaf-wrapped bundles steamed until tenderSliced thin and quickly seared for stir-fries or tacosGround or finely chopped and formed into patties with added starch for lamb burgers

Tips & pitfalls

Render fat slowly over medium heat — high heat will seize the fat and toughen the surrounding meat
Marinate no longer than 2–4 hours; acid breaks down surface texture and causes mushiness
Always rest the meat 5–10 minutes after cooking to redistribute juices throughout the fat-marbled flesh
Score the fat cap in a crosshatch pattern before grilling to prevent curling and ensure even rendering
For maximum crispness, start the meat in a cold pan and bring it to heat gradually — the fat will render out evenly
Save the drippings — they are liquid gold for flavoring beans, grains, braising liquids, or pan sauces
Cook to 145°F (63°C) internal for medium doneness; carryover heat will add 5–10 degrees
When braising, add aromatics to the liquid — the fat-soluble flavors penetrate deeply
Do not discard the bones from bone-in flap; simmer them for stock or add to the braising liquid for extra depth
If the fat cap is thicker than 3/4 inch, trim some off and render it separately for cooking fat

Nutrition

180kcal

Energy

753 kJ · per 100 g

Where the calories come from

Protein 48%Carbs 0%Fat 52%

Protein

21.7g

43% DV

Carbs

0% DV

Fat

10.3g

13% DV

Fiber

0% DV

Sugars

of which

Sodium

87mg

4% DV

Notable micronutrients

Vitamin B1289% DV

Niacin (B3)29% DV

Zinc29% DV

Phosphorus13% DV

Riboflavin (B2)11% DV

Vitamin B67% DV

Source · USDA FoodData Central · Lamb, New Zealand, imported, flap, boneless, separable lean only, raw

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In the shops

Matched grocery products

No matched grocery products for Lamb Flap yet.

Good to know

Cut type: Lamb belly, lower rib and flank area; includes rib bones and fat cap in one piece
Fat content: 35–45% fat by weight, layered throughout with thick fat cap
Primary regions: New Zealand, Australia, Hawaii, Pacific Islands
Typical weight: 2–4 lbs per piece, sold bone-in or deboned
Flavor profile: Rich, lamby, slightly gamey; collagen renders to soft, unctuous gelatin
Texture cooked: Fork-tender when braised; can turn chewy if subjected to high heat only
Fresh storage: Refrigerate 1–2 days, wrapped tightly to prevent fat oxidation
Frozen storage: Up to 3 months, airtight wrapping essential
Yield: Near 100% — minimal trim if portioned correctly
Skill level: Easy to cook; success depends on patience for proper fat rendering

Substitutes

Pork belly — Closest texture and fat ratio; different flavor but works well for braising, grilling, and crisp-frying
Pork spare ribs — Similar fat-to-meat ratio and bone-in configuration; works for braising and slow roasting
Lamb shoulder — Significantly leaner; add pork fatback or bacon fat when grinding to approximate flap's richness
Beef short ribs — Different cut and species, but similar suitability for low-and-slow cooking and comparable fat content

Pairs with

Garlic Rosemary Soy sauce Coconut milk GingerBrown sugar or molassesTaro leavesOrange or lemon

Also called

Lamb Flaps (Sip Sip) · Mutton Flap · Sip Sip