In a stand mixer bowl combine half the milk with the yeast and let it bloom for 5 minutes. Add the flour and salt and mix, it will be really dry that’s ok. Cover and let rest 20 minutes.
Add the egg and milk and using the hook knead for 5 minutes. While you wait cut the rolled bun into small pieces. Once the 5 minutes is passed, add the slices piece of bread and knead for another 3 minutes. Cover and let rest an hour.
It’s now time to shape the dough. You want to roll it to form somewhat of a baguette about 8-9 inches long. It will need to fit in your pot.
I rolled it about 10″ and as you can see below it expanded to 12″ ( the size of my pot) and wouldn’t move anymore. I would recommend doing 2 instead of 1 big.
Put water in a large pot and bring to a boil. Add a tbsp of salt and add the dough to the water. Cook for 8 minutes. Turn the dough in the water so it boils the other side and cooks for 9 minutes.
Remove the dough from the water and place it on a cooling rack. Using a toothpick, pierce a few holes so the steam from inside the bread can exit.
Let cool at least 5 minutes before cutting it in slices with a serrated knife.