step 1
Cover tin of milk in cold water and simmer for 30 minutes
step 2
Cool tin under running cold water and leave in fridge over night or up to a week
step 3
Empty milk and sugar into bowl and whisk for 5 minutes
step 4
Carry on whisking and Slowly add lemon juice
step 5
Whisk until all lemon juice is incorporated and mixture thickens
step 6
Pour into pastry case. Leave to set for about 30 minutes
step 7
( do not put in fridge)