Prawns (or Shrimp) in coconut gravy

Prawns (or shrimp - I honestly don't know the difference) are the only seafood I have attempted making. I only take a crack at it occasionally as I hate the time it takes to clean them properly. Even if I buy them shelled and deveined, I still put in that effort as my husband reacts to it badly otherwise. Aside from this, the recipe actually needs very little time and effort to prepare.

250g king prawns or shrimp (shelled and deveined)
1/3 cup freshly grated coconut
1 tbsp whole coriander seeds
1 tsp cumin seeds
1 tbsp whole peppercorns
2-4 whole dried red chillies
1/2 tsp fenugreek seeds
1 medium onion, finely chopped
2-3 tsp tamarind pulp
1/2 tsp turmeric powder
Salt to taste
1tbsp oil (coconut oil if you have it)

Tempering
5-6 curry leaves
1 tsp mustard seeds

• Toast coriander seeds, cumin seeds, peppercorn, red chilli and fenugreek in a dry pan for a few minutes till they release their natural oils and become fragrant. Allow them to cool and then grind them along with the fresh coconut to a fine paste. You can remove the seeds from the chillies to control the heat.
• Meanwhile heat oil in a saucepan. Add the mustard seeds and curry leaves to the hot oil and let them splutter.
• Add the chopped onions and turmeric. Fry in the oil till the onions soften and turn translucent.
• Add the ground coconut paste and fry till the oil starts to separate. This may take about 3-5 minutes. Keep stirring to prevent the paste from catching at the bottom.
• Add the prawns and toss them in the paste for a couple of minutes. 
• Add salt to taste and enough water to form a gravy. Bring to a boil first and then cover and cook on a low heat for 4-5 minutes. The prawns will turn opaque when they are fully cooked.
• Add enough tamarind pulp at this stage to give the gravy some sourness and boil for a few more minutes before turning off the heat.
• Serve with hot rice.