Identify the application: tempering/finish, long simmer, raw garnish, or baking — choose the substitute grouped for that use.
Measure the substitute at the stated ratio (e.g., for 8 curry leaves use 1 kaffir leaf or 1 bay leaf for long simmer).
If substituting dried/crushed curry leaf, bloom it in hot oil for 20–30 seconds before adding other aromatics to rehydrate and release oils.
For lime zest + curry powder swaps, add the zest late in a cook or fold into dry mixes in baking to preserve volatile citrus oils; add 1 teaspoon neutral oil if a fatty mouthfeel is needed.
When using fresh herbs (Thai basil), add at the end of cooking or as a garnish to preserve aroma — heat destroys basil’s volatile top notes within 2–3 minutes.