For the slice base
175g gluten free plain flour
50g ground rice
85g golden caster sugar
140g cold lactose/dairy free butter, diced
1 tbsp lactose/dairy free milk
For the lemon topping
zest 3 lemons, plus 200ml/7fl oz juice (about 4 lemons)
200g caster sugar
25g rice flour
icing sugar, to dust
Heat oven to 200C/180C fan/gas 6.
Line a 21 or 22cm square, shallow baking tin with baking parchment.
Put the gluten free flour, ground rice and sugar in a bowl with the lactose/dairy free butter and rub in until fine crumbs form.
Stir in the lactose/dairy free milk with a cutlery knife.
Tip into the tin and press down evenly.
Bake for 15-20 mins until golden.
Remove the tin and lower oven to 180C/160C fan/gas 4.
Mix the lemon juice and eggs, then sieve into a bowl with the sugar, rice flour and zest.
Whisk to combine, pour over the base, then bake for 10-15 mins until the top is just set.
Cool in the tin, dust with icing sugar, then slice.
Recipe adapted from: Good Food