Garlic: Peel, rinse, and drain well (avoid excess water to prevent spoilage). Smash with the back of a knife, then chop into coarse pieces to retain texture. Lightly rinse the chopped garlic and drain again.

Thai chili pepper: Remove stems, wash, and drain. Chop into small pieces or mince. (Wear gloves to avoid irritation.)

Heat 300ml oil over medium heat until about 50% hot (small bubbles appear with chopsticks).

Lower to small flame, then add shredded onion, scallion white, star anise, bay leaves, and cinnamon stick.

Stir-fry for 3–5 minutes until golden and aromatic.

Remove aromatics with a slotted spoon and discard or save. Keep only the infused oil.

Keep heat on low, add chopped garlic, and stir constantly for 3–5 minutes until moisture evaporates and garlic turns lightly golden (don't burn it).

Add Thai chili pepper, stir-fry another 2–3 minutes until aroma is fully released.

Add salt and sugar, stir well, and raise to medium heat.

Cook 5–10 minutes longer if there's excess liquid. Continue until sauce thickens, oil separates, and mixture looks glossy.

While hot, pack the sauce into clean jars and press down to compact.

Pour a thin layer of oil on top (prevents air contact and spoilage).

Seal the jars and refrigerate after cooling.

Keeps well in the fridge for 3–6 months. (Use clean utensils and finish soon after opening.)