In a pan, bring the milk, sugar and salt to the boil while stirring. Turn down the heat, reduce to approx. 300 ml for approx. 30 mins., stirring occasionally. Stir the gelatine into the hot milk. Pour the mixture through a sieve into a bowl. Leave to cool, chill until just set at the edges. Beat the cream until stiff, fold into the mixture, cover and chill for approx. 3 hrs.
Whisk the dulce de leche with the reserved cream until smooth.
Mix the strawberries with the sugar and lemon juice, leave to absorb for approx. 10 mins. Using two tablespoons, shape the mousse into quenelles, plate up and decorate with the dulce de leche sauce and strawberries.