Tamarind Prawn Curry

Name: Tamarind Prawn Curry
Ingredients: 2½ cup (5½ oz) coriander seeds; ¾ cup (2½ oz) cumin seeds; 15 whole cinnamon sticks (1¾ oz.); ⅓ cup (1½ oz.) fennel seeds; 2 Tbsp. plus 1 tsp. (1 oz.) green cardamom seeds; 2 Tbsp. plus 1 tsp. (½ oz) fenugreek seeds; 1 Tbsp. (¼ oz.) black mustard seeds; 1 Tbsp. (⅛ oz.) cloves; 14 oz. jumbo shrimp, head and shell on; ½ tsp. ground turmeric; 1 tsp. flaky sea salt, divided, plus more; 2 Tbsp. coconut oil; ¼ tsp. fenugreek seeds; 8–10 fresh curry leaves; One 1-in. cinnamon stick; 8 Thai shallots or 4 medium shallots, finely chopped; 2 garlic cloves, finely chopped; 1 Tbsp. plus 1½ tsp. unroasted curry powder; 1½ tsp. Kashmiri chile powder; 1 tsp. ground coriander; 1 medium vine-ripe tomato (3½ oz.), finely chopped; ⅔ cup coconut milk; ¼ cup strained tamarind extract; 1 tsp. sugar, plus more; 1 Indian green finger chile, halved lengthways (optional); 3 Tbsp. coconut oil; 6–8 whole curry leaves; 3–4 dried Sri Lankan chiles; 2 garlic cloves, thinly sliced