In a large mixing bowl, combine the bread flour, salt, instant yeast, and sugar.
Add the softened butter to the bowl and mix everything together with your hands or a wooden spoon.
Gradually add the lukewarm water to the mixture, mixing it in well until a dough forms.
Knead the dough on a floured surface for about 10 minutes until it becomes smooth and elastic. Or, you can use a stand mixer.
Place the dough back in the mixing bowl, cover with a damp towel, and let it rest in a warm, draft-free place for about an hour or until it has doubled in size.
Grease a Pullman tin with some butter or oil.
Punch down the risen dough and shape it into a rectangle that is roughly the same size as the Pullman tin.
Place the dough into the greased Pullman tin, cover with a damp towel, and let it rise for another 30 minutes.
Preheat the oven to 375°F (190°C).
Remove the towel from the Pullman tin and put the lid on.
Bake the bread in the preheated oven for 35-40 minutes, or until the top is golden brown and the loaf sounds hollow when tapped.
Remove the bread from the tin and let it cool on a wire rack.
Slice and serve as desired.