Instructions

Fry the shallots

• Put the shallots in a wide bowl, add the flour, and toss to coat, separating the rings as you go. Put them in a sieve over the bowl and shake off the excess flour.
• Heat the oil in an 8-inch skillet over medium-high heat until shimmering hot. Add the shallots in batches and fry until crisp. Transfer to paper towels to drain as fried. Set aside.

Make the laksa

• Soak the noodles in a bowl of cold water for 30 minutes to soften.
• Meanwhile, in the bowl of a food processor, process the garlic, chiles, cilantro stems, lemongrass, and lime leaves, and turmeric with 2 Tbs. water to make a paste, or pound using a mortar and pestle.
• Bring the coconut milk to a boil in a 6-quart pot over medium-high heat, stirring occasionally. Add the spice paste, palm sugar, and tamarind, if using, and stir well until the sugar is dissolved. Add the crab, bring back to a boil, then turn off the heat and let it sit for 5 minutes, or until the crab is just cooked through (an instant-read thermometer inserted in the center of the crab should read 145°F).
• Add the fish sauce, lime juice, cabbage, and tofu. Turn the heat back on to medium-high and cook for 1 minute, then remove from the heat.

To serve

• Divide the noodles and crab among four bowls, spoon over the sauce and garnish with the bean sprouts, herb leaves, and crisp-fried shallots. Serve with the lime halves.