Bring a large pot of salted water to a boil and cook the spaghetti according to the package instructions.

Meanwhile, place a dry skillet over medium heat and add the sunflower seeds. Toast them for a few minutes, stirring frequently, until lightly golden. Remove from the heat and let cool slightly.

Add the sun-dried tomatoes, oil from the jar, garlic, and toasted sunflower seeds to a blender or food processor.

Season with salt and blend until smooth. If the pesto seems too thick, add a little more tomato oil or a splash of water until it reaches your desired consistency.

Drain the spaghetti and return it to the pot.

Add the red pesto and toss until the pasta is evenly coated. If needed, add a little extra oil to help everything combine smoothly.

Serve immediately, topped with vegetarian Parmesan if desired.