Combine flour, salt, yeast, and sugar in a medium-large bowl. Stir well to combine. Set aside.
Place butter in a medium-size microwave-safe bowl and cook on high power for 40-60 seconds or until melted. Stir in the milk then add the egg and yolks and stir well. Combine the hot water and potato flakes. Stir for 15-20 seconds to dissolve the potato flakes. Make a well in the center of the flour mixture. Add the egg/milk mixture and the potato water. Stir, from the bottom up, until the dough comes together in a shaggy mass. The dough will be thick. Keep scraping the sides and bottom of the bowl until every last bit of flour is incorporated.
Drizzle a little oil (I use olive oil but any oil will do) over the top of the dough to keep it from drying out. Cover the bowl with plastic wrap or a plate and set the bowl in a warm place (see Café Tips above in the post for how to create a warm, cozy rising spot) for 1-1 ½ hours or until the dough is doubled in size.
Sprinkle ¼ cup of flour onto a work surface. Scrape the dough onto the floured surface. Turn the dough with a dough scraper or spatula until it’s thoroughly coated with flour.
Divide the dough into 20 portions, each one about 1.8 ounces (or 50g). (I like to use a kitchen scale for this but you can just eyeball it.) Roll each ball of dough to coat with flour. (You may need a bit more flour.)
Holding a piece of dough in your dominant hand, tuck the edges under with the other hand , rotating the dough so that all the edges get tucked under and the top has formed a smooth round ball. (If the dough feels sticky while shaping the rolls, just roll it in a little more flour.)
You can stop at this point and place the dough balls on the prepared baking sheets but here’s how to form perfect balls - put a drop or two of oil (again I use olive oil but any oil will do) on a clean area of your counter. Rub the oil with your hand to create a thin coating on the counter surface. Now place one of the tucked under balls of dough on this oiled area and roll it with your hand to create a perfectly round ball. Place the ball of dough on one of the prepared sheet pans. Repeat with remaining portions of dough.
Cover rolls with a clean kitchen towel and allow to rise for 30-45 minutes in a warm area. They should start to puff up but won’t be doubled in size this time.