Coconut Laksa With Shrimp (Coconut-Curry Noodle Soup With Shrimp)

Ingredients

• 1 1/2 pounds medium shrimp—shelled and deveined, shells reserved
• 1 onion, quartered
• 1 carrot, sliced
• 3 large shallots, quartered
• 4 jalapeños, seeded and coarsely chopped
• 1/3 cup thinly sliced fresh ginger
• 1/4 cup macadamia nuts
• 1 teaspoon ground coriander
• 1/2 teaspoon ground turmeric
• 1/4 cup asian fish sauce
• 1/4 cup canola oil
• 1 (14 1/2-ounce) can unsweetened coconut milk
• 2 plump lemongrass stalks—bottom 8 inches only, outer layer removed, stalk cut into 2-inch lengths
• 2 tablespoons light brown sugar
• 1 pound thai flat rice noodles (pad thai), soaked in warm water for 10 minutes
• salt
• lime wedges, for serving