Dissolve yeast in water and mix in sugar for about 5 minutes. Add flour. Place in oiled bowl and let rise for 1 hour. Once proofed, shape dough into buns weighing 70-85 grams each. Brush with egg white and milk. Place on parchment lined surface if using a metal baking pan or lightly flour baking surface if using a pizza stone. Preheat oven to 175 C (350 F). While oven is heating, allow dough to complete final rise (covered, underneath a towel) for at least 15 minutes before going into oven. Cook for 20-25 minutes.