Peel and slice the apples, then put them into a pan with the sugar, ½ pint water, lemon juice, and lemon zest.
Simmer until tender, and rub through a fine sieve.
Bloom the gelatin in the 2 tbsp water. Melt the bloomed gelatin, strain it, and stir it into the apple mixture, and turn into a prepared mould.
Chill in the fridge for a few hours until set.