Cut the chili so that you're left with just the red part of the plant and put them in the oven preheated at 180°C (356°F) to roast for 10 minutes or until dehydrated. Put them in a bowl to cool when ready.Tip: Line the tray with foil to prevent any sticking.
Meanwhile, finely chop the garlic, red shallots and galangal.
Chop the lemongrass roughly into 1-2 cm (0.4-0.8") segments.
Use a food processor to blitz the lemongrass, then pour into a bowl and set aside for later.
Repeat the previous step with the roasted chilis.
Pour the annatto seeds into 2 US cup oil in a saucepan and keep the heat on low to infuse the color into the oil for 3-5 minutes or until red. Use a sieve to strain the seeds from the oil into a bowl.
In a new saucepan or wok, combine 1 US cups oil with the star anise and Chinese cinnamon bark on low heat for 2 minutes or until the aromatics begin to bubble.
Remove the star anise and Chinese cinnamon bark and add the chopped garlic, red shallots and galangal to brown for 1 minute.
Pour in the lemongrass, chili, dried chili flakes, fish sauce, salt, sugar and chicken bouillon powder and stir for 10 minutes or until golden.
Pour in the annatto seed oil and stir to combine for 1 minute.
Let the Sa Tế cool and store in airtight containers to be enjoyed with your meals!