Bring a large saucepan of water to a boil. Once boiling, salt the water generously and add the pasta. Cook according to the package’s instructions for al dente pasta.

Before draining, scoop out at least 1 cup (240 mL) of pasta water. Drain the pasta but do not rinse it.

Heat a 12-inch skillet or Dutch oven over medium-high to high heat. Add the olive oil. Once hot, add the onions and season with salt and pepper. Stir frequently and cook until a light brown fond starts to form on the surface of the pan, about 5 minutes. Add a few spoons of water to deglaze the pan.

Continue cooking the onions, adding more water every few minutes and stirring frequently to prevent burning, until they’re deeply golden brown, about 15 minutes.

Reduce heat to medium and stir in the sliced garlic. Cook for another 5-10 minutes until the onions are fully caramelized and the garlic is golden and soft, adding water as needed to deglaze.

Add the red pepper flakes and oregano; stir to coat the onions for about 30 seconds.

Add the tomato paste and stir constantly until the paste has caramelized and become darker, about 2-3 minutes.

Add the tamari, nutritional yeast, and chopped sundried tomatoes and stir to combine. Turn the heat to low.

Ladle a few spoons of the reserved pasta water into the caramelized onion mixture. Transfer the hot cooked pasta to the onions. Use tongs to swirl the pasta into the sauce, adding more pasta water as needed until all noodles are coated in the sauce. This usually takes 3-4 minutes.

If desired, garnish with pine nuts and chopped parsley. Leftovers stay good in an airtight container for 2-3 days.