1 cup warm water
2¼ teaspoons active-dry yeast (1 packet)
3 tablespoons sugar
2 tablespoons vegetable oil
1 large egg
1 teaspoon salt
3¾ cups all-purpose flour
½ cup shredded mozzarella
1. In a large bowl, mix the yeast, warm water, sugar, oil, egg and salt. Gradually add the flour and mix until a dough forms. When the dough is too dense to mix, use your hands.
2. On a floured surface, knead until the dough becomes soft and smooth, about 5 to 10 minutes. Place the dough in a bowl, cover and rise in a warm part of the kitchen until it doubles in size, at least 1 hour.
3. Separate the dough into 3 even pieces. Use a rolling pin to flatten the first piece of dough into a 9 by 9 inch square.
4. Spread 1 tablespoon of pizza sauce, ½ cup cheese and some cooked mushrooms or sliced olives. Roll it up carefully, trying not to rip the dough (this can be tricky, so take your time). Pinch the ends, then set the strand aside. Repeat for the other two pieces of dough.
5. Stretch each of the strands to 12 inches in length. Braid and transfer to a non-stick baking tray.
6. Preheat the oven to 350°F / 175°C. Brush the challah with a beaten egg and sprinkle with mozzarella. Allow the challah to rise in a warm part of the kitchen until it looks light and poofy, at least 1 hour.
7. Bake on the middle oven rack until the top is perfectly golden, about 30 minutes.