Place Sichuan peppercorns and fennel in a piece of muslin, tie with kitchen string and combine in a saucepan with soy, garlic, spices, 1 tsp salt and 1 litre water. Bring to the boil over medium-high heat, reduce to medium and simmer for 5 minutes to infuse. Add soy beans to spiced liquid and simmer over medium heat until bright green (3-4 minutes). Drain well, transfer to a bowl and cool. Eat by pulling beans from pods with your teeth.
Note Cassia bark is available from Asian grocers. If unavailable, substitute with cinnamon quill. Frozen soy beans are available from Asian supermarkets. You can also use fresh soy beans if they’re available. Rub salt on pods to remove hairy fibres before cooking for 7-10 minutes.