1. Activate the Yeast: In a large mixing bowl, combine the warm water, active dry yeast, and granulated sugar. Stir gently and let it sit for 5-10 minutes until the mixture becomes foamy. This indicates your yeast is active and ready to work.

2. Combine Wet Ingredients: Add the active sourdough starter and 2 tablespoons of olive oil to the foamy yeast mixture. Stir until well combined.

3. Mix Dry Ingredients: In a separate bowl, whisk together the all-purpose flour and salt. Gradually add the dry ingredients to the wet ingredients, mixing with a wooden spoon or a stand mixer with a dough hook until a shaggy dough forms.

4. Knead the Dough: Turn the dough out onto a lightly floured surface and knead for 5-7 minutes, or until the dough is smooth and elastic. It should spring back slightly when poked. If using a stand mixer, knead for 4-5 minutes on medium speed.

5. First Rise: Lightly grease a clean bowl with olive oil. Place the dough in the bowl, turning it once to coat. Cover the bowl with plastic wrap or a clean kitchen towel and let it rise in a warm place for 1.5 to 2 hours, or until doubled in size. The dough should feel soft and airy.

6. Shape the Bread Bowls: Gently punch down the risen dough to release the air. Divide the dough into 4 equal pieces. Shape each piece into a tight, round ball. Place the shaped dough balls on a baking sheet lined with parchment paper, leaving ample space between them.

7. Second Rise and Preheat: Cover the shaped dough balls loosely with plastic wrap or a kitchen towel and let them rise again for 30-45 minutes, or until noticeably puffy. During this time, preheat your oven to 400F (200C).

8. Bake the Bread Bowls: In a small bowl, whisk together the beaten egg and 1 tablespoon of water to create an egg wash. Brush the tops of the risen dough balls with the egg wash. Bake for 25-30 minutes, or until the bread bowls are golden brown and sound hollow when tapped on the bottom.

9. Cool and Serve: Transfer the baked bread bowls to a wire rack to cool completely before slicing off the top and hollowing out the center to create the bowl for your soup.