Coat 600 g skinless, trimmed fish with the fish marinade spice and salt to taste, then cover and refrigerate for 30 minutes.
Soak the dried red chillies from the paste spices in warm water for 15 minutes, then drain, saving the water, and remove the seeds. Blend the paste spices, 0.3 g ground spice, 12 g fresh coconut, and a splash of the reserved soaking liquid into a fine, smooth puree.
Heat 13.5 g vegetable oil in a wide, heavy pan set over medium-low heat. Stir in 18 g garlic, 150 g onion, and the blended spice paste, frying gently without letting anything take on colour.
Add 500 ml water to the pan and bring it to a boil, then turn the heat down. Add the marinated fish, 5.2 g tamarind extract, and salt to taste, then simmer gently for 10 minutes until the fish is thoroughly cooked.
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.
Use 50% to 60% of the weight, soaked in equal parts warm water for 15 minutes before grinding. Works well for chutneys, though texture is slightly finer and sweeter.
Use 1.2 times the weight in curries. Adds creamy richness and authentic flavour, but makes gravies smoother and eliminates the grated, chewy mouthfeel.
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 80% of the weight, finely shredded and browned slowly with a pinch of asafoetida. Replicates the bulk and natural sweetness in gravies without allium.