Put the pasta on first - place a large pan of water on to boil. When the water comes to the boil, add the pasta and simmer for 12-13 minutes, until cooked.
Meanwhile, heat the oil in a large frying pan over a medium-high heat.
Season the salmon fillets with the salt and pepper. Place in the pan skin-side-up.
Fry the salmon for 3 minutes, until golden, then turn the salmon over and move it to one side of the pan.
Add the onions to the space left in the pan. Cook on a medium heat for 3-4 minutes, stirring occasionally, until softened.
Stir in the minced garlic and cook for a further 30 seconds.
Add in the passata, tomato puree, dried thyme, and sugar. Stir together and allow to simmer for 2-3 minutes.
By now the pasta should be nearly ready. Add the spiralized courgette (zucchini) to the pan with the pasta for the last 30 seconds of cooking. Then drain the pasta in a colander, reserving a cup of the cooking water.
Turn the salmon over in the frying pan. Remove the skin using a set of tongs and discard.
Break up the salmon using the back of a fork into chunky pieces. Stir the cream into the sauce.
Add the cooked spaghetti and spiralized courgette to the pan along with a good splash (about ¼ cup) of the pasta cooking water.
Use a set of tongs to toss the spaghetti in the sauce, distributing the pieces of salmon amongst the pasta. TIP: Add more of the pasta cooking water if you want to loosen up the sauce further (optional).
Divide the pasta between bowls and top with a little grated parmesan, black pepper, and a sprinkling of fresh basil leaves.
