In the bowl of a stand mixer, combine the discard, water, butter, yeast and sugar. Using the dough hook and your hand, stir the ingredients before placing the bowl onto the mixer stand. Add the salt and the flour and place bowl on stand mixer, turn on and mix medium-low for about 10 minutes.
If needed, add extra flour about 1-2 tablespoons at a time, until dough comes together and is no longer a sloppy mess. Try not to over-flour the dough; it should still be very 'loose' and stretchy but smooth. After 8-10 minutes, rip off a small piece of dough and see if it passes the window pane test (stretch small piece of dough and see if it can let light through without tearing.)
Once dough is mixed thoroughly, place into a lightly greased container, cover with towel and watch for it to rise, until at minimum doubled in size. Usually 1-2 hours, depending on how warm your kitchen is. While waiting, grease a small-medium sized pan for the bread rolls to be baked in and set aside.
Once dough has risen, punch it down and plop onto countertop. Using a bench scraper, evenly divide and cut into 10 rolls. If you are extra like me, place dough on kitchen scale and divide total weight by 10, then using a bench scraper, cut pieces of dough per weight. Each roll will be more consistent in size if you weigh it but its not necessary. Shape each dough piece in a ball, so the smooth side is facing up and the gathered side is touching the pan. Place in prepared pan and cover with a towel for the second and final rise before baking. This will usually take 60 minutes for them to double in size.
While rolls are rising, preheat oven to 350℉. Optional, create an 'egg wash' of your choice. I mix milk and agave in a small bowl and brush on the tops right before going in oven. Bake for 20-25 minutes, depending on size of rolls and pan etc. Remove from oven when tops are nicely golden brown and internal temperature is 200°-210℉. option to brush with butter straight out of the oven but not necessary. Allow to cool slightly so they are warm not hot.