Step 1

Add water and yeast to a bowl and then add flour and salt; knead until a soft dough is formed. Cover and leave at room temperature for 30 minutes.

Step 2

Refrigerate for a minimum of 8 hours or a maximum of 24 hours. (you can also freeze for up to 3 months.)

Step 3

Add onion and oil to a medium sized pan and heat over medium heat for about 20 minutes until onions are reduced by about 1/3.

Step 4

Transfer to a bowl and add breadcrumbs and poppyseeds and salt. Set aside until needed.

Step 5

Add water and flour in the bowl of a stand mixer and mix for 2 minutes, then let it rest for 20 minutes.

Step 6

Add the pâte fermentée (not all is needed; only 1/2 cup), yeast, and salt and mix on low speed until the dry ingredients are completely combined.

Step 7

Increase the speed to medium and mix until the dough is smooth and pulls away from the sides of the bowl (about 5 to 7 minutes). Do the windowpane test to see if dough is finished.

Step 8

Transfer the dough to a clean bowl and cover with plastic wrap or a very slightly damp towel and let rise for about 1 to 1.5 hours until doubled in size.

Step 9

After it has risen, punch down dough and then divide into 12 equal pieces (about 80 grams each). Shape the pieces into balls and let them rest for 5 minutes.

Step 10

After 5 minutes, flatten the balls with palm of hand or a rolling pin until they are about 4 inches in width and then place then on cornmeal-lined baking sheets (or you can simply use parchment paper or baking spray).

Step 11

Cover the trays loosely with plastic wrap and let rise for about 1 hour.

Step 12

After the bialys have puffed up, make an indent in center of each bialys with thumb or spoon and place 2 tablespoons of filling (also top with cheese if using).

Step 13

Preheat the oven at 500F for at least 30 minutes. If you have a pizza stone or steel, it is helpful to use one.

Step 14

Bake the bialys in the center (I didn't bake my directly on the stone or steel, but rather placed my baking tray directly on top of my pizza steel - this helps to prevent burning).

Step 15

Bake until lightly browned, about 12 to 14 minutes.