Step 1

Bring a large pot of water to a boil, salt it generously and cook the pasta al dente according to the instructions on the package. Reserve some pasta water before draining.

Step 2

Meanwhile, make the sauce. Heat the olive oil in a large, deep skillet and melt the butter in it. Add the onion and cook over medium heat for 3-4 minutes until slightly softened.

Step 3

Stir in the garlic and continue to cook for another minute until fragrant. Next, add the lemon juice, the chopped pistachio and double cream.

Step 4

Lower the heat and simmer for 1-2 minutes until the sauce thickens. Stir in the fresh basil, then transfer the cooked pasta to the pan and stir to combine. Add a dash of pasta water if the sauce looks too thick.

Step 5

Stir in the grated Parmesan and rocket salad, season to taste, and serve immediately.