Mix the sourdough starter with warm water and sugar in a large bowl until well combined.

Add the bread flour and salt gradually, stirring until it forms a shaggy dough.

Knead the dough on a floured surface for about 10 minutes until smooth and elastic.

Incorporate the sun-dried tomatoes by folding them into the dough.

Rise the dough in a covered bowl at room temperature for 4-6 hours or until doubled in size.

Shape the risen dough into equal portions and form each into a bagel shape.

Boil water in a large pot and add a tablespoon of baking soda. Drop each bagel into the water for about 30 seconds per side.

Bake the bagels on a lined baking sheet at 425°F for 20-25 minutes until golden brown.