Indian pantry and substitutions
Indian bay leaf/tejpatta is not European bay leaf. Curry leaves have no close substitute; skip or pivot rather than pretending bay leaves will do the same job.
Hing/asafoetida is powerful and often important in lentil or no-onion/no-garlic cooking. Kashmiri chile brings color and mild heat; cayenne changes the balance. Garam masala is an aromatic finishing family, not one universal spice mix.
Tamarind, kokum, amchur, anardana, yogurt, vinegar, tomato, and lime are different acids, not one generic sourness. Match the acid to the region and dish.
Commercial masalas can be excellent when matched to the dish: sambar podi, chaat masala, goda masala, xacuti masala, biryani masala, garam masala, panch phoron. The error is using a generic curry powder when the dish has a specific spice logic.
Ghee, mustard oil, coconut oil, gingelly/sesame oil, and neutral oils each point in different directions. If the defining fat is missing, name the shift.
Atta/wheat flour, rice, lentils, chickpea flour/besan, millets, coconut, yogurt, and region-specific legumes or grains often matter as much as the spice box.