Mix the flour and salt in a large bowl, stir in the sugar and yeast, then rub in the butter. Add enough water and mix to form a soft dough.
Knead the dough on a lightly floured surface for up to 10 minutes until smooth and elastic.
Shape the dough on a baking tray or place in a tin, cover and leave to rise in a warm place until doubled in size for 30 to 45 minutes. Preheat the oven to 220°C.
Bake the loaf for 15 minutes, then reduce oven temperature to 190°C and bake for a further 15-20 minutes, or until the bread is risen and golden brown and sounds hollow when tapped underneath. Turn out and cool on a wire rack.