Add flour to a big bowl. Then sugar and yeast in one side of the bowl, and salt on the other side.
Add egg and milk to the bowl too. Mix roughly. Then add the utane dough as well.
Knead the dough until smooth. Add the butter in. Continue to knead again until the dough is smooth. Cover with cling film/damped cloth and prove for 45 mins at a warm place.
In the meanwhile, cut 3 slices of spam.
To cook the omelette, heat up the pan and keep it at medium heat. Pour a thin layer of egg into the pan just enough to cover the whole pan. Tilt the pan so that the egg spread evenly. When it's cooked, divide the egg horizontally into 4 parts, flip the outer parts to the middle, and again towards each other. Put the omelette to one end of the pan and pour the rest of the egg. Tilt the pan so the egg spread evenly. Once it's cooked, roll the omelette over and create more layers. Cut the omelette into 3 equal pieces.
When the first proof is done, take the dough out of the bowl onto a floured surface. Press out all the air. Split equally into 3 doughs. Leave it to rest for 10 mins.
Roll it out to a long rectangular shape. I like to have a fluffier bun on the top, so I keep the center thicker than the two ends.
First, add one egg omelette, then spam. Bring the two ends together, and close it tightly. Repeat for the rest.
Cover it for the second proof for 30 mins.
Preheat the oven to 175°C.
Brush some egg wash on top of the buns and bake it for 12-15mins.