Coconut Cod Chowder With Seasoned Oyster Crackers

Name: Coconut Cod Chowder With Seasoned Oyster Crackers
Ingredients: 1½ lb. skinless, boneless cod or halibut fillets; 2½ tsp. kosher salt, divided, plus more; 5 Tbsp. ghee or unsalted butter, divided; 2 medium leeks, white and pale green parts only, halved lengthwise, thinly sliced crosswise; 6 garlic cloves, thinly sliced; 1 3 piece ginger, peeled, cut into matchsticks; ¾ tsp. ground turmeric; ¾ tsp. ground coriander; ½ tsp. ground cardamom; 1 serrano chile, thinly sliced; 12 oz. baby Yukon Gold or red potatoes, halved; 2 13.5-oz. cans unsweetened coconut milk; 2 celery stalks, thinly sliced, plus leaves for serving (optional); 1½ cups oyster crackers; 1 tsp. paprika; 2 limes, divided