Place the fresh yeast, sugar, water and milk in a bowl and leave to stand for 10 minutes until the yeast dissolves.
Add the flour, salt, egg and soft butter in a mixing bowl and start kneading.
Add the sugar, water, milk and yeast mixture and knead for a good 5 minutes. If needed, add a little more flour or water.
The dough should be quite elastic and come away from the sides of the bowl.
Roll out the dough, place it in the bowl, cover it and let it rise for 1 to 2 hours at room temperature.
While the yeast is rising, prepare the icing. In a bowl, whisk together the icing sugar and lemon juice until you have a thick glaze that holds together.
Colour the icing as desired and set aside.
After the yeast has risen, cut out discs of dough with a cookie cutter and make a hole in the centre.
Place the doughnuts on a baking tray covered with baking paper and leave to rise for another 15 minutes (cover with a clean dry cloth).
In a deep fryer or pan, fry the doughnuts over medium heat in sunflower oil. Turn the doughnuts halfway through to brown both sides!
Once golden brown, remove the doughnuts from the oil and place on a paper towel to remove excess oil.