In a small saucepan or tadka pan, combine the neutral oil, cinnamon stick, black cardamom, star anise, coriander seeds, bay leaf, crushed black pepper, chopped garlic, and onion. Mix everything together so the ingredients are fully submerged.

Place the pan over very low heat. Let the oil come to a gentle simmer, where you see small, consistent bubbles. Cook for about 20 minutes, or until the oil is fragrant and the garlic and onion have slowly turned a beautiful golden brown. This low-and-slow process is key to drawing out all the flavours without burning the ingredients.

Turn off the heat. Stir in the red chilli flakes, red chilli powder, sesame seeds, sugar, salt, and soy sauce. The residual heat from the oil will toast the spices and chilli flakes, releasing their full flavour.

Allow the chilli oil to cool completely before transferring it to an airtight glass jar. It will stay fresh and flavourful for up to two months.