Take Yeast in a bowl.
Add sugar and lukewarm water to the yeast and whisk well.
Leave the mix for 5 minutes.
Take flour in a bowl, add salt and oil to it.
Mix well and add the yeast mix to the bowl.
Whisk them well and add egg yolk to it.
Mix them to make a dough.
Add some milk and mix to make a sticky fluffy dough, followed by a tbsp of butter.
Mix the dough well. Cover the bowl with a transparent sheet.
Leave it for an hour.
After an hour check if the dough is lighter and fluffier.
Collect the dough together and add some oil, mix well and cover it with a transparent sheet again.
Leave it for another 30 minutes.
Grease a baking tray with butter and put a butter paper over it.
Now take out the dough, add some oil and mix well.
Make small balls out of the dough and put them in the baking tray.
Cover it well with a transparent sheet and leave it on for another hour.
After an hour, take the baking tray out and brush them with egg white.
Bake them at 180 degrees Celsius for 20 minutes.
Brush the baked dinner rolls with butter.
Serve with tomato ketchup.