From the amazing "Cook Real Hawaii" by Sheldon Simeon.
Warm the milk to a temperature between 100 and 110 degrees Fahrenheit (37-43 C) either in the microwave or on a stovetop
Combine the milk with 1 tsp. of the sugar and yeast, and allow the yeast to bloom for 10 minutes
Crack one of the eggs and separate out the yolk from the white, setting the white aside for later
Mix the evaporated milk, remaining sugar, button, 3 eggs plus the 4th yolk, lemon zest, and nutmeg in a bowl, then mix in the yeast mixture
In another bowl, mix the flour, potato flakes, and salt, then pour the wet ingredients into the dry ingredients
If you have a stand mixer, mix this using a dough hook for several minutes until a wet and sticky dough forms. You could also do this by hand with a spoon
Once the dough has at least come together, turn the dough out onto a well-floured surface, and knead the dough for several more minutes. If the dough is too sticky to work, add a bit more flour. The dough should be wet and sticky, but dry enough you can work it into a smooth ball
Set the dough ball in a lightly buttered bowl and cover, then let it sit for at least an hour, allowing it to double in size
Butter the inside of a 9x13 baking pan
Punch down the dough and dump it onto another lightly floured work surface
Divide the dough into 16 equal sized pieces, and roll each piece into a ball
Set each ball into the pan, cover again, and allow to rise for an hour, giving each ball enough room so that ideally they aren't touching eachother
Preheat the oven to 350 degrees Fahrenheit (177 C) while the dough is rising
Mix the reserved egg white well with a bit of water and brush the egg white on top of each roll, then bake in the oven for 20 to 25 minutes
Brush the tops with a bit of butter and serve warm or cool, either way they will be delicious!