Preheat the oven to 220c. Sift the flour into a bowl and use your fingertips to rub in the butter until it looks like breadcrumbs. Make a well in the centre and pour in the combined milk and water.
Mix quickly into a soft dough and turn onto a lightly floured surface. Knead lightly. Press or roll out to a circle 1 cm thick.
Put the pizza base on an oiled oven tray. Mix together all the topping ingredients and spoon over the pastry, leaving a border round the edge.
Bake doe 20 minutes. Cut into slices and serve with salad.