Mix flour and butter in a bowl, adding yeast and salt to opposite sides.
Gradually stir in the water until a soft, non-sticky rough dough forms.
Turn the dough onto a work surface lightly greased with oil.
Fold and turn the dough repeatedly until lightly coated in the oil.
Knead the dough for 5 minutes until it becomes smooth and stretchy.
Place dough in an oiled bowl, cover, and let double in size for about an hour.
Line a baking tray with silicone or baking paper.
Knock back the risen dough, roll it to remove air, and shape into a round loaf.
Place on the tray, cover, and let double in size again for another hour.
Preheat the oven to 220°C and place an empty roasting tin at the bottom.
Dust the loaf with flour and score a 1cm deep diamond pattern on top.
Place the tray in the oven and pour cold water into the bottom roasting tin.
Bake the loaf for 30 minutes until golden.
Cool the loaf on a wire rack once it sounds hollow when tapped on the bottom.