Use a pair of kitchen scissors to cut open the chillies then remove and reserve the seeds. Pulse (or grind with a pestle and mortar) the skins, discarding any stalks, until the consistency of shop-bought dried chilli flakes. Tip into a large bowl. Toast the szechuan peppercorns, cumin seeds and black peppercorns in a frying pan until smelling toasty, then tip into the spice grinder and whizz into a powder. Tip into the bowl with the star anise, peanuts, ginger, salt and sugar, as well as half of the reserved chilli seeds, or more if you prefer it hotter.