Prawn Cocktail With Caramelised Grapefruit, £1.15

To serve 4, generously. For the full shopping list, see here. 200g small prawns, £2 (Smartprice at Asda, frozen) 90ml/6tbsp seafood sauce, 36p (£1/250ml, Tesco) salt and pepper, <1p 1 can of grapefruit, £1.10 (Del Monte) 130g shredded iceberg lettuce, 35p (Growers Selection at Asda) 200g cherry tomatoes, 48p (Nightingale Farms at Tesco) half a cucumber, 32p (Growers Selection at Asda) First defrost your prawns overnight in the fridge – best to do this in the sealed bag they came in to catch the excess liquid that comes out as they defrost. If you forget, and we all do, you can leave them in a bowl of cold water, covered, at room temperature on Christmas morning, but squeeze one between finger and thumb to make sure it is fully defrosted an hour or so before assembling to serve. Drain your prawns well and gently squeeze them out, and transfer to a small bowl. Mix with the seafood sauce and a little salt and pepper, and set to one side. Drain your grapefruit juice, reserving the …