For the knots, in a large mixing bowl, place water and sourdough starter, whisking to combine. Then, add bread flour, instant yeast, and salt to the bowl, and mix until it creates a shaggy dough. Cover and let sit for 10 minutes to allow the gluten to hydrate/develop, then knead for 2 minutes. If the dough is too tacky/hard to work with add 1-2 tablespoons flour and knead until well-mixed. You want the dough to be hydrated but not pulling apart too easily.

Cover bowl with plate and set bowl in a warm place for the first proofing. For this, if my kitchen is under 75F (24C), I turn on my oven light and store the bowl in there (temp is typically 80F or 27C), to expedite the rise. Once the dough has doubled in size, which should take about an hour or so if in a warm area, remove the covering.

Dust your work surface with flour and punch the air out of the dough. Cut your dough into 12 even pieces (about 50g each), then shape them into roughly 8x1-inch (20x2.5 cm) logs, then tie each one into a loose knot. Place them in a large cast iron skillet or on a baking pan, that has been brushed with a thin layer of olive oil. Cover them with a warm, damp towel and let them rise for another 30 minutes, or until they are a little less than double in size.

In the last 10 minutes of rising, preheat oven to 425F (220C or gas mark 7), and in a small bowl, whisk together 2 tablespoons (30 ml) olive oil, garlic powder, and salt until combined. Once knots have risen, brush garlic oil mixture over the tops of them, and sprinkle with cheese shreds. Bake for 23-28 minutes, or until lightly browned on the top. (If making sauce, do this while the knots are baking) Once baked, take out of oven and let cool for at least 5-10 minutes before serving. (sprinkle with herbs if desired)

For the sauce, in a small pot, heat the tomato paste and garlic over medium heat until the mixture begins to brown and sizzle, about 2 minutes. Add the tomato sauce, sugar, onion powder, dried oregano, and dried basil and cook, stirring often, until warmed through, 3 to 5 minutes longer. Season with salt and black pepper to taste. Store in the refrigerator for up to 7 days or in the freezer for up to 6 months.