Cook the pasta according to package directions until al dente. Reserve about 100ml of the pasta cooking water before draining.

While the pasta cooks, heat the olive oil or butter in a large pan over medium heat.

If using, add the finely chopped onion and cook until softened and translucent, about 3-4 minutes.

If using, add the minced garlic and cook for another 30 seconds until fragrant.

Reduce heat to low. Stir in the sour cream and mayo. Cook gently for 1-2 minutes, stirring constantly, until the sauce is smooth and heated through. Do not boil.

Add the flaked smoked salmon to the sauce and stir to combine. Season with salt and black pepper.

Add the drained pasta to the pan with the sauce. Add a splash of the reserved pasta water and toss everything together until the pasta is well coated and the sauce reaches your desired consistency. Add more pasta water if needed.

If using, stir in the chopped fresh dill or parsley.

Serve immediately and enjoy your delicious, creamy pasta!