Melt the butter and add to the lukewarm water. Combine the flour, salt and yeast in a big mixing bowl and mix thoroughly. Make a well in the middle of the flour and pour about half of the water-and-butter mixture into the well. Work the flour and water with your hands, adding more water as needed. When the dough is well combined and sticky, place it on a floured surface and knead it until it becomes springy and elastic. This takes about 10 minutes.
Place the dough back into the bowl, cover with a clean tea towel and put in a warm place. Allow the dough to rise for 40 minutes to an hour, or until it has doubled in size. Knock the dough down and knead for another couple of minutes. Place the bread dough in prepared loaf tins or make round loaves and place on a baking sheet. Allow the loaves to rise again until they have doubled in size.
In the meantime, preheat the oven to 180 ªC . If you have made round loaves, bake for 40 minutes; if you have used loaf tins, they’ll take about an hour. If the bread sounds hollow when tapped, it’s ready. Remove the bread from the baking sheet or tins and cool on wire racks.