Prawns and Páramos

I'd planned the meal, bought the food, marked the page in the recipe book. My 20-year-old nephew is here for the weekend and I'm treating him to proper home food. He's training to be a boxer in between studying product design at Nottingham University. He's six foot tall and struts his well-toned and not-insubstantial muscles round my kitchen like a peacock. His mother is a chef, so not only was moules frites his favourite dish when he was six, but these days he knocks up shakshuka for his uni...