Dissolve yeast and sugar in 1/4 cup lukewarm water and let stand for 5 minutes. Stir in sifted flour, eggs and oil and knead into a soft, elastic dough. Add more flour as needed. Shape int a ball, coat with oil and let rise for 1 hour.
Divide dough into 4 portions. Shape each into a ball and roll into a strand. Braid strands of dough, then place dough on a greased baking sheet. Cover and let rise for 30 minutes. Brush dough with egg and bake in an oven preheated to 200°C (approximately 400°F) for 45 minutes. Remove, let cool slightly and serve.