Dissolve the yeast in the water with 1 teaspoon of the sugar. Beat well and leave for 10 minutes, until it froths.
In a very large bowl, lightly beat the eggs. Then add the salt, sugar, honey (optional) and oil and beat again. Add the frothy yeast mixture and beat well. Now add the flour gradually, and just enough to make a soft dough that holds together, mixing well, first with a large spoon, then working it in with your hands.
Knead vigorously for about 15 minutes, until it is very smooth and elastic, adding flour if the dough is too sticky.
Add any optional mix-ins when the dough is almost ready.
Pour a little oil in the bowl and turn the dough, so that it is greased all over.
Cover the bowl with a damp towel and put it in a warm place to rise for 2-3 hours, or until it has doubled in bulk. Punch the dough down, then divide into 2 pieces to make 2 loaves (or one large loaf).
Braid challah into desired shape and place on a baking sheet lined with parchment paper or a silicone baking mat, leaving plenty of room for them to expand. Allow them to rise for 1 hour, or until doubled in bulk.
Now brush gently with the beaten egg yolk (with a few drops of water), or if you want to sprinkle with poppy or sesame seeds, brush first with the whole beaten egg (the seeds stick better if the white is there too)
Bake in a preheated 350F oven for 20-25 minutes (a bit longer if you’ve made one large loaf) or until the loaves are beautifully golden-brown. They are done if they sound hollow when you tap the bottoms.