Poaching is not the only way of cooking prawns. (Grey ones, I'm talking about; pink ones are cooked already.) You can fry them too. Because a hot frying pan is a less efficient cooking medium than simmering water, it may help you not to overcook them.
For a starter for four people, I had an ungenerous 16 prawns (I had been nervous about how much I was going to be charged). I chopped two Scotch bonnet chillis (having taken out the seeds and the membranes); I also used a tbsp of soy sauce, and a dstsp of sesame oil.
I heated a thin layer of groundnut oil in a frying pan over a medium heat, and threw in the prawns. When are they ready? When they go pink, is the supposed rule; but they went pink almost immediately. I gave them a couple of minutes. I allowed the heat to die down a little, and stirred in the chilli, soy sauce and sesame oil.
We ate the prawns at room temperature, with our hands, and with bread for any spare sauce.