1: Place the garlic and 1 teaspoon of the sugar in a small mixing bowl and mash to a paste with the back of a spoon. Add the remaining sugar, lime juice, fish sauce, cold water, and pepper and whisk until the sugar is dissolved. Correct the seasoning, adding lime juice, fish sauce, or sugar to taste: The dressing should be highly seasoned. The dressing can be made up to 1 hour ahead.

2: Just before serving, line a plate with paper towels. Clip a deep-fry thermometer to the side of a saucepan so that the tip does not touch the bottom of the pan; add the oil and start frying when the temperature reaches 375°F. Deep-fry the shredded brisket until sizzling and crisp, 2 minutes. Work in batches as needed so as not to overcrowd the pan. Transfer the brisket with a wire skimmer or slotted spoon to the prepared plate to drain.

3: Pour the dressing into a large serving bowl. Stir in the fried brisket shreds. Add the pineapple, cucumber, chiles, scallions, and herbs. Toss to mix. Sprinkle with the peanuts and serve.