Cut butter in small pieces and place in a microwave-safe bowl. Microwave on high for 30 seconds until mostly melted (a few lumps are fine) and set aside.

Microwave the wholemilk in a microwave-safe mug or measuring cup for 15 seconds until warm but not hot (about 35°C).

Transfer the warm milk into a large bowl and whisk in the sugar.

Sprinkle yeast over the milk, mix and set aside for 10 minutes. The yeast should start to get bubbly and look like foam.

Pour the cooled butter into the milk mixture and add the egg. Whisk to combine and break up the eggs.

Place your flour in a medium size bowl add the salt and mix. Add the wet mixture to the flour, then add the vanilla essence and nutmeg and use a wooden spoon to mix all together until a sticky dough forms. The dough will be very tacky and messy to work with. You may be tempted at this stage to add some more flour. Please do not. Oil your working top and transfer the dough onto it. Oil your hands as well and knead the dough until it becomes smooth, elastic and less tacky, about 10-15 minutes. Because the dough is very tacky, you may have to use your fingers to knead it and a dough cutter to assist in lifting the dough from the working top whenever you feel you need to turn it over. Persevere with this step.

Form the dough into a rough  ball and transfer it in a large, lightly greased bowl and cover it  with a clean tea towel and place in a warm spot in your home and allow it to prove at room temperature for about two hours.

Transfer the dough onto a working top. It will now feel less tacky. Pat the dough down. This step helps remove some of the gas bubbles formed by the yeast during the rising process. Break small pieces of approximately 30 grams from the dough and roll each piece, in the palm of your hands, into rough small balls. Do not press to hard, or you will deflate the dough too much and ensure that the surface of the balls are very smooth. Keep to the 30 gram because if you make them any bigger it will make your bouldou too big  bearing in mind that the  bouldou will expand during second proofing and also during frying.

Place the balls on a baking tray lined with grease proof paper. Cover with a clean kitchen towel and let rise until puffy, at least 30 minutes.

Pour oil into a large heavy-bottomed pot or a wok. You have to have enough oil so that the bouldou can float freely. Heat over medium-high heat until the oil reaches approximately 170°C. Use a flat spatula and transfer the balls into the oil. If the balls stick to your greaseproof paper when you try to lift them to fry, you may decide to cut the grease proof paper in strips and lift a strip with the balls one at a time  and slide both the balls and the paper into the hot oil, and then remove the paper with a pair of tongs. That way the bouldou will hold its shape. I have found out that trying to move them by holding them might deflate them before they hit the oil.

Fry the bouldou for 45 seconds on each side, or until puffed and golden brown. Turn them over a few times to ensure even colour. You may have to adjust the heat if the temperature rises too high.

Using a slotted metal spoon, remove them from the hot oil and in order to drain any excess oil, immediately place them onto a paper towel

Allow them to cool. They can be eaten as is. However, should you wish a sweeter treat you may decide to dust them with some sugar or drizzle some honey on top.