Slice 400g (14oz) of the strawberries and add to a saucepan with the sugar and 120 ml (4 fl oz) water, cover and cook gently for 5 minutes until the fruit is softened. Meanwhile put the remaining 4 tablespoons of water into a small heatproof bowl, sprinkle over the gelatine so that the powder is completely absorbed by the water then leave to soak for 5 minutes.
Purée the cooked strawberries and their juice in a liquidiser then press through a sieve and discard the seeds.
Heat the bowl of gelatine in a small saucepan of gently simmering water until it forms a clear liquid. Gradually stir the gelatine into the fruit purée then mix in the lemon juice and leave to cool.
Slice the remaining strawberries or chop if large, stir into jelly mixture then pour into 6 x 150 ml ( ¼ pint) individual moulds or one large dish. Stand moulds or dish on a baking tray then chill in the fridge for 4 hours or until set.
To serve dip each mould in hot water and count to 10, take out of the water, loosen the edge of the jelly with a wetted finger, invert mould on to a serving plate, holding mould and plate, jerk to release, remove mould and repeat with other moulds. Decorate with tiny sugar flowers or hearts and serve with a little cream or custard.