In the extra-large bowl, place 4 Tbl. of oil. Set aside.

In the large bowl, add 1 cup olive oil, honey, warm water, and yeast. When the yeast proofs, add the rolled oats, 10 eggs, whole wheat pastry flour, and sea salt. Mix using a wooden spoon, making sure to break up all the egg yolks.

Allow the contents of the large bowl to stand in order to sponge the dough, 20 minutes to an hour. Longer is also fine.

Add the unbleached white flour 2 cups at a time, mixing in each addition prior to adding more flour.

Turn out contents of the large bowl onto a well-floured surface. Knead until dough rebounds quickly when poked with a finger. If it gets sticky, add a bit more flour to the board. You will have to add flour several times. Do not knead until dough doesn’t pick up any more flour. This will make it too dry!

Place dough in the extra-large, oiled bowl. Spin dough 180° around, and then flip dough over twice so that upper and lower surfaces are coated with olive oil.

You may place extra-large bowl into a 150°F-170°F oven for 40 minutes, OR in a cold oven for 2-5 hours OR in the refrigerator for 5-24 hours. Take a look at your day, and choose the speed that suits. If you are using the refrigerator, try to move it to the counter about an hour before you want to handle it, as cold dough is tougher to shape.

Turn out onto a dry, wooden board. Knead for about 5 minutes, until the dough feels uniform. If it gets sticky, add olive oil to the board, not flour.

Pinch an olive-sized piece of dough (“challah”), place it in a corner of one of the parchment-lined jelly roll pans, and say the bracha.

Shape into four 4-strand braids. Tuck ends under, and place two braids on each of the parchment paper-lined pans. NOTE: the best braid is with 4 strands. See The Joy of Cooking or Youtube for instructions on how to braid four-stranded challah.

Let challahs rise in their shapes for 15 minutes, only, at 150-170°F.

Coat with egg wash (egg + some water) using a pastry brush. Sprinkle with poppy or sesame seeds.

Bake at 340°F (convection oven)-350°F (conventional) for 18 minutes. Swap pans left/right, front/back and top/bottom for even baking. Bake another 10-15 minutes until light to medium brown. There should be a hollow sound when you tap each loaf. Do NOT over-bake.

Turn out onto wire racks to cool. If you’re using parchment paper, you may let the loaves rest on the parchment paper with the wire rack under it. Don’t wrap them right away in foil, as the bottom crusts will become soggy.