In a 4-quart Dutch oven, heat ½ tablespoon of olive oil over medium heat. Once the oil shimmers, add the Italian sausage, breaking it apart as it browns for about 5-7 minutes. Stir occasionally to ensure even cooking, then remove the sausage and set it aside, leaving the drippings in the pot for added flavor.

Add the remaining olive oil to the same pot over medium heat. Toss in the chopped onion, red, yellow, and orange bell peppers, and minced garlic. Sauté for about 3 minutes, stirring frequently until the vegetables soften and become fragrant.

Pour in the white wine, scraping the bottom of the pot with a wooden spoon to release the flavorful browned bits. Allow the wine to simmer and reduce by half, approximately 3-4 minutes.

Stir in the undrained diced tomatoes, Italian seasoning, red pepper flakes, salt, and freshly ground pepper into the pot, mixing well. Let the sauce simmer and cook for about 10 minutes.

Return the browned Italian sausage to the pot, incorporating it into the sauce. Add the chopped parsley and let everything warm together for another 5 minutes over low heat.

While the sauce simmers, cook the egg noodles according to the package instructions in a pot of salted, boiling water to al dente, about 6-8 minutes; drain the noodles and set aside.

Add the drained egg noodles to the pot with the sauce, tossing everything together gently to ensure the noodles are well-coated for about 1-2 minutes over low heat.