Rinse the dried chilies quickly (they are air-dried outdoors and dusty) and spread them in a single layer on a sheet pan to dry while the oven heats. Use 100 g er jing tiao, 100 g lantern chilies, plus 10-50 g seven-star chilies depending on how hot you want it. Roast at 300F / 150C for 15 minutes, pull the pan out, shake it, and let them cool for 10 minutes. Return to the oven for 10 more minutes at the same temperature until everything is one shade darker, then shake again and let them cool completely. A chili should shatter easily when squeezed; if it still bends, give it 5 more minutes.

Snap the er jing tiao and seven-star chilies into short pieces by hand and tear the lantern chilies in half. Shake most of the seeds out (too many make a gritty oil) but keep a small pinch back for their nutty aroma. Pound in a mortar and pestle, or pulse in a food processor - do not blend to dust. Grind about two-thirds to medium-coarse flakes and the last third to a fine powder for layers of texture.

Weigh the ground chili blend and multiply by five - that is exactly how much oil you need. The golden ratio is one part chili to five parts oil, by weight, which for the video's 250 g of chilies works out at about 4 1/2 cups (roughly 1 litre). Divide the ground chili evenly between two bowls, making bowl one the large one since everything ends up in it.

Soak 3 star anise, 1 piece of cassia snapped in half, 3 small pieces of sand ginger, 5 bay leaves, 2 black cardamoms with the seeds removed, and 1/2 tsp fennel seeds in 1/2 cup of warm water. This hydrates them so they release flavour without scorching. Meanwhile slice 2 pieces of ginger, cut the white part of 1 Chinese long onion into chunks, slice 1/2 onion, and cut 5 scallions plus a small handful of cilantro into 3-inch lengths.

Heat the measured oil in a heavy pot over medium-low heat and add all the fresh aromatics; let them fry gently, because high heat only burns them. Once they start browning, add the drained dry spices and cook about 2 more minutes until the spices look dry and the aroma is deep. Strain the oil clear of every solid part into a clean, dry pot - nothing should stay behind to keep cooking.

Bring the strained oil to 375F / 190C. Ladle just enough over the chili in bowl one to cover it, stirring fast and hard the whole time - this is the aroma layer, and the chilies darken and smell roasty. Let the oil in the pot fall to 285F / 140C, tip the contents of bowl two into bowl one, stir once, then immediately pour in all the remaining oil while stirring - this is the colour layer, where the bright red comes back. When the mixture cools to about 210F / 100C, stir in 3 tbsp toasted white sesame seeds and 3 small pieces of crushed rock sugar.

Cover the bowl loosely and leave it at room temperature overnight, about 12 hours, so the chilies keep giving colour and aroma. Stir, then transfer to clean jars and store in the fridge, where it keeps for at least a few months. Stir before each use, as the chili settles.