Fill a large pot with water and bring it to a rolling boil over high heat. Salt the water generously before adding the pasta. Cook until al dente, typically 7-10 minutes.

In a large skillet, heat 2 tablespoons of oil over medium heat. Add the onions with a pinch of salt and sauté for about 5 minutes until they soften.

Continue cooking the onions for about 15 minutes on medium-low heat, stirring frequently, adding a tablespoon of water to help deglaze the skillet.

Stir in minced garlic, Italian seasoning, and optional red pepper flakes. Sauté for another 3-4 minutes until fragrant.

Before draining the pasta, reserve about 1 cup of starchy pasta water. Then drain the pasta and add it to the skillet with the onion mixture along with sun-dried tomatoes, balsamic glaze, and tamari.

Gently fold in the pasta and chopped parsley, adjusting thickness with reserved pasta water as needed until creamy.

Plate and serve warm, optionally garnished with extra parsley.