Whisk the bread flour, vital wheat gluten, and sea salt in a medium mixing bowl until well combined.
Create a well in the center of the dry ingredients and add the sourdough starter, liquid egg whites, water, and honey.
Mix by hand until a rough, shaggy dough forms, then transfer to a clean surface and knead for 8 minutes until smooth and elastic.
Place the dough in a lightly oiled bowl, cover with a damp cloth, and let ferment in a warm environment for 5 hours.
Gently shape the risen dough into a tight round boule and place it onto a piece of parchment paper.
Preheat a small Dutch oven inside your oven at 425°F for at least 30 minutes to ensure even heat.
Score the top of the loaf with a sharp knife in a cross pattern, carefully lower it into the hot Dutch oven, and bake covered for 20 minutes.
Remove the lid and continue baking for 10 minutes until the crust is deeply browned and sounds hollow when tapped.