Grease four 13 × 6½ × 5cm (5 × 2¾ × 2inch) baking tins. Put the yeast, sugar and milk in a small bowl and mix well. Leave in a draught-free place for 10 minutes, or until bubbles appear on the surface. The mixture should be frothy and increased in volume.
Put the flour and 1teaspoon salt in a large bowl, make a well in the centre and add the yeast mixture, the oil and 250ml (9fl oz/1cup) warm water. Mix to a soft dough and gather into a ball. Turn out onto a floured surface and knead for 10 minutes. Add a little extra flour if the dough is too sticky.
Place the dough in a lightly oiled bowl. Cover with plastic wrap or a damp tea towel and leave in a draught-free place for 1 hour, or until well risen. Punch down the dough, turn out onto a floured surface and knead for 1 minute, or until smooth. Divide into four portions, knead into shape and put in the tins. Cover and leave in a draught-free place for 45 minutes, or until risen.
Preheat the oven to 210°C (415°F/Gas 6–7). Brush the loaf tops with the beaten egg. Bake for 10 minutes, then reduce the oven to 180°C (350°F/Gas 4) and bake for a further 30–35 minutes, or until golden and the bread sounds hollow when tapped on the base. Cover with foil if the tops become too brown.