Preheat a deep-fat fryer or heavy pan with oil to 190°C.
Dry fry black and Sichuan peppercorns in a hot pan until aromatic.
Crush the toasted peppercorns coarsely in a pestle and mortar and stir in sea salt.
Mix the crushed spice mixture with sliced chilli and breadcrumbs in a bowl.
Dredge squid rings sequentially in flour, beaten egg, and the breadcrumb mixture.
Fry the breaded squid pieces until light golden brown and crisp.
Drain squid on kitchen paper and season with salt and lime juice.
Caramelize caster sugar in a hot pan until it reaches a light caramel colour.
Stir in rice vinegar, salt, and chillies, then cook for two minutes and cool.
Dissolve sugar in rice wine vinegar and lime juice over heat for the dressing.
Pour the hot dressing over cucumber balls and let sit for at least five minutes.
Drain the cucumber and toss with fresh coriander leaves.
Serve the squid alongside the salad with the chilli dip on the side.