3-4 Shallots - 1 medium onion and one extra clove of garlic
Palm Sugar - brown sugar & 1 tsp molasses
Aromatic ginger - yellow ginger or omit
Fresh Galangal - equal amounts of ginger. However finding powdered galangal would be a better alternative especially if there is already ginger in the recipe.
Fresh Turmeric - you can always go for dried. However, if you cannot find turmeric at all, cumin can be substituted as it has a similar bitter taste.
Candle nut is a waxy cream-coloured nut similar in size and texture to macadamia nut which can be used as a substitute. Raw almonds or cashews will also suffice.
Lemongrass substitutions call for grated ginger and lemon zest. If there is already a large call for ginger in this recipe, omitting the additional ginger and adding some lemon zest can’t hurt.
Kaffir Lime Leaf - 1/2 a small bay leaf. 1/4 tsp of lime zest
Lemon Basil - Thai Basil or Holy Basil, if you cannot find these you can use ground star anise or the regular basil but the flavour profile will change!
Shrimp Paste - for 1 tbsp shrimp paste = 3 tbsp fish sauce, if you can’t find fish sauce you can always try to mix 1 tbsp soy sauce with either anchovy fillet, miso paste or Worcestershire sauce.