Rinse 750 g shellfish thoroughly in cold water to clear away any sand or grit; leave in or remove the shells as you prefer.
Combine the marinade spices with 5.1 g lime juice and a pinch of salt to taste, rub the mixture thoroughly over the shellfish, then cover and refrigerate for 20 minutes.
Blend the ground spices with 2 tablespoons of water in a small dish to make a paste.
Place a heavy pan over high heat and warm 13.5 g vegetable oil. Add 2 g grated ginger, 1 teaspoon chopped garlic, and the whole spices, frying for roughly 1 minute until the spices begin to splutter.
Tip in 12 g chopped green chilli and the ground spices paste, stirring constantly for 30 seconds. Add 300 g sliced onion and sauté for 2 minutes until translucent.
Stir in 300 g diced potato, 1 teaspoon sugar or jaggery, salt to taste, and 250 ml water. Turn the heat down to low, cover, and simmer for 10 minutes.
Add the marinated shellfish along with any resting juices, 120 g skinned tomato, and 125 ml water. Cover and continue simmering for another 10 minutes until the sauce has thickened.
Scatter 0.3 g ground mace over the curry, take the pan off the heat, and mix in 1 tablespoon coconut feni.
Use 50% of the weight and stir in near the end of cooking. Adds warmth and depth since it contains ground coriander, but introduces stronger spices like clove and cinnamon.
Use 20% to 25% of the weight (1 g for every 4 to 5 g fresh). Stir into the gravy; adds peppery heat and warmth, though it misses the crisp, zesty kick of raw root.
Use 15% to 20% of the weight (about 1 g for every 5 to 6 g fresh cloves). Whisk into sauces; gives a savoury, toasted garlic flavour without raw pungency.
Use 1 g ground for 4 g whole (or 1 small pinch per 2 to 3 whole cloves). Add with spice powders; disperses intense warmth quickly, so use with restraint.
Allspice berries
Use 100% of the weight whole in tempering. Imparts a warm, clove-like aromatic profile combined with hints of nutmeg and cinnamon.
Use about a third of the weight (0.5 g ground for a 2.5 cm piece), stirred in with the ground spices rather than fried whole, since the powder burns quickly.
Use 80% of the weight, finely shredded and browned slowly with a pinch of asafoetida. Replicates the bulk and natural sweetness in gravies without allium.
Use 40% to 50% of the fresh tomato weight mixed with a splash of water. Imparts a deeper red colour, thicker sauce, and slightly sweeter cooked flavour.
Steep a tiny pinch (0.1 g per 2 g turmeric) in 2 tbsp warm water; use to match the rich golden hue. Contributes an aristocratic, honeyed floral flavour rather than earthy bitterness.