Pour the warm water into a large bowl and add the salt. Mix briefly to dissolve the salt.
Sprinkle in the dry yeast. Let it sit for a minute, then stir to combine.
Add the sunflower oil and mix it into the liquid.
Start adding the flour gradually, mixing as you go so it hydrates evenly.
Knead the dough for about 5 minutes, until it becomes smooth and slightly elastic.
Shape the dough into a ball, transfer it to a clean, dry bowl lightly dusted with flour. Cover the bowl with a kitchen towel and let the dough rise in a warm place for 1 hour.
The dough has now risen and increased in volume.
Transfer the dough onto a lightly floured work surface and knead it briefly. Shape it into the type of loaf you prefer.
Place the shaped loaf into a baking pan lined with parchment paper and cover it with a kitchen towel. Let it rise again for 20 minutes.
The bread has risen and puffed up in the pan.
Beat the egg and brush it over the surface of the bread using a pastry brush.
Score the top of the loaf with a sharp knife so it can open nicely in the oven and avoid random cracks.
Preheat the oven. Bake the bread for 20 minutes at 410°F (210°C), then reduce the temperature to 355°F (180°C) and bake for another 20 minutes, until deeply golden.
Let the bread cool completely, then slice and serve.