Tom Nuong Sa
“Whole prawns threaded onto split lemongrass stalks, brushed with fish sauce-sugar-chile-lemongrass marinade, grilled over charcoal until the shells turn coral-red and edges blacken.”
Where it comes from
Tom nuong sa belongs to the seafood-grill tradition of Vietnam's central coast — Hue, Hoi An, Da Nang, Nha Trang — where evening grills are set up on the beach or along the lagoons. The pairing of prawn with lemongrass appears wherever lemongrass grows, but using the stalk itself as a skewer is a coastal technique that doubles the lemongrass exposure (mince in the marinade, plus stalk core releasing oil during grilling). The dish also appears at central-region weddings and as one course in a multi-prawn 「tom 5 mon」 (five-prawn-course) menu.
On the plate
Shells are coral-orange streaked with black at the legs and tail, glossed with caramelized fish-sauce sugar; the lemongrass mince has crisped against the shell into fragrant flecks. First move: suck the head — the brain butter has mixed with the marinade. Then peel; the flesh is taut, sweet, with lemongrass perfume that has worked through the shell. Lime-pepper-salt at the table. The thinner the lemongrass mince, the deeper the perfume — coarsely chopped lemongrass falls off and burns.
How it works
Two tricks separate this from a generic grilled prawn. First, leaving the shell on traps moisture and concentrates flavour — the shell takes the char, the flesh stays juicy; peeled prawns dry out in 90 seconds on the same grill. Second, the marinade rest is capped at 20 minutes because nuoc mam is salty enough to denature prawn protein; longer and the texture turns mealy. The fine-minced lemongrass adheres to the shell during the rest; on the grill, the cellulose chars and the trapped oil migrates inward through the perforated back-shell into the flesh.
Central-coast (Hue, Hoi An, Da Nang, Nha Trang) lemongrass-skewered prawn. Shell stays on — it takes the char while the flesh inside steams in its own juice. Marinade capped at 20 minutes because nuoc mam is salty enough to denature shrimp protein and turn it mealy.
Variations
Hoi An lagoon-side stalls grill over coconut-husk charcoal for sweeter smoke; Nha Trang seafood streets serve as one of five courses in tom 5 mon; Phu Quoc island-version uses local nuoc mam from the Phu Quoc fish-sauce houses (Khai Hoan, Thinh Phat).
On the Palate
Ingredients
Serves 4
How it's made
5 steps · Show ↓25 min active · 25 min waiting
How it's made
5 steps · Show ↓- 18 min
Choose 16 large head-on prawns (40-50g each, U15 size). Use scissors to slit the shell down the back; lift out the dark vein but keep the shell intact. Pat dry.
- 222 min
Mince 4 lemongrass stalks (white parts) extremely fine — like fine sand. Mix with 2 tbsp nuoc mam (fish sauce), 2 tbsp sugar, 1 tsp salt, 2 minced bird's-eye chiles, 3 minced garlic cloves, 1 tbsp neutral oil, 1 tsp annatto oil for colour. Toss prawns through the marinade; rest 20 minutes — not longer or salt firms the flesh.
Watch outDo not marinate longer than 20 minutes, or the salt will firm the flesh.
- 38 min
Take 8 lemongrass stalks (15cm each), bruise the bottom, split lengthwise. Thread two prawns onto each stalk through the body — one head-up, one head-down. Reserve marinade for basting.
- 45 min
Grill over hot charcoal (or 240°C grill pan) 2 minutes per side, basting once with reserved marinade. Shells should bright coral-red with black edges; flesh just opaque — total 4-5 minutes for U15 prawns. Overcook by 60 seconds and they go rubbery.
Watch outOvercooking by just 60 seconds can make the prawns rubbery.
- 54 min
Plate on banana leaf or a wooden board. Serve with muoi tieu chanh dip (juice of 2 limes + 2 tsp salt + 2 tsp ground black pepper + 1 sliced bird's-eye chile, mixed at the table), extra lime wedges and a small bowl of nuoc cham. Eat with hands; the shell carries enough caramelized marinade that you suck before peeling.
