In a large mixing bowl, whisk together the dry ingredients: 4 cups of all-purpose flour, 1/2 cup of sugar, 1 tablespoon of salt, and 1 tablespoon of instant yeast until well combined.

In a separate bowl, mix the wet ingredients: 1/2 cup of warm water and 1/2 cup of vegetable oil, then add in 3 large eggs. Stir well.

Gradually pour the wet ingredients into the dry ingredients while mixing with a wooden spoon or your hands until a sticky dough forms.

Transfer the dough onto a floured surface and knead for about 10 minutes or until the dough becomes smooth and elastic.

Place the dough in a greased bowl, cover it with a damp cloth or plastic wrap, and allow it to rise in a warm area for about 1 hour or until it doubles in size.

Once risen, punch down the dough and divide it into three equal portions. Roll each portion into long ropes (about 12 inches), then braid them together.

Place the braided dough on a greased baking sheet and cover it once again with a damp cloth. Allow it to rise for another 30 minutes.

Preheat your oven to 350°F (175°C).

Beat one egg for the egg wash, and gently brush the surface of the dough. If desired, sprinkle sesame or poppy seeds on top.

Bake in the preheated oven for about 30-35 minutes or until the challah turns a golden brown color.

Once baked, transfer the bread to a wire rack to cool before slicing.