Blend 140g butter, flour and salt with your fingertips or a fork until mixture resembles coarse breadcrumbs. Add water and mix with hands, forming a smooth dough; chill for 1 hour. Roll pastry out on a floured surface to cover a 23cm tart tin; set aside.
Beat the eggs and milk together in a bowl. Melt the sugar in a pan over medium heat until it forms a syrup, 3 to 5 minutes. Slowly pour the syrup into the beaten eggs; stir in 55g butter and vanilla essence.
Cover the pastry base with half of the pecans. Spoon the syrup over the top; cover with remaining nuts.
Bake in preheated oven for 10 minutes. Reduce the temperature to 180 C / Gas mark 4; continue baking until bubbly and brown, about 45 minutes. Allow to cool before serving.