Mix lukewarm water with yeast and sugar in a small bowl and let stand for about 10 minutes.
Put the flour, salt, oil and milk in a bowl. Pour the foamy yeast over it and mix everything together well. Knead a smooth dough out of it. Rub the dough ball with a little oil and let rise for 1 hour (at least until the volume has doubled).
Divide the dough and roll out a large circle at a time. Divide this into 8 pieces of cake (like you would cut a pizza, for example). Roll up from the broad side and shape into a half moon.
Preheat the oven to 200 °.
Place the croissants on a baking sheet lined with baking paper, with the tip facing down, let rise for another 30 minutes. Bake for about 15-20 minutes until they are golden brown.
If you like, these croissants can also be sprinkled with poppy seeds or sesame seeds. To do this, whisk a little egg before baking, brush the croissants with it and sprinkle with seeds.