For the chilli dressing, heat a frying pan over a medium heat and add the dried chillies. Keep them moving around the pan for a minute or two, until they start to darken in colour and smell toasted. Remove from the pan and put into a mortar. Pound the roasted chilli, then add the palm sugar or brown sugar. Continue pounding, adding the lime juice and the fish sauce. Mix well and place to one side.
Preheat the oven to 160˚C/325˚F/Gas 3. Preheat the vegetable oil in a wok or a deep fat fryer if you have one.
To prepare the squid, pull out the tentacles, and trim their tops to remove the beaks. Open out the squid body and, using a small sharp knife, gently score the inside surface of the squid, taking care not to cut all the way through. If the squid are large, cut them into quarters. If using baby squid, these can be simply halved. Set aside. Pound peppercorns and sea salt together in mortar and pestle, then add flour and set to one side.
Peel half the garlic and pound with the remaining whole garlic cloves. They should split open and the flesh and the skin should come together. Throw the pounded garlic into the preheated oil, including the skins. Lower the heat to a bubble and leave to cook for a good 5 minutes, stirring every so often. The garlic will float to the top and be crisp. Using a slotted spoon, remove the garlic and drain on kitchen paper.
Place the pan back over a high heat and when the oil starts to shimmer, it’s ready to cook in (or use a kitchen thermometer and heat the oil to 190˚C/375˚F). Toss the squid in the seasoned flour so that is coated well.
Drop a quarter of the squid into the oil and fry for about 4-5 minutes. As it cooks, it will curl up and go crisp and lightly browned. Once cooked, remove the squid from the oil using a slotted spoon and drain on kitchen paper set onto a baking tray. Keep warm while you cook the remaining squid.
Place the garlic with the picked coriander in a large bowl and add the cooked squid, toss well and serve on individual plates with the dressing around the outside.