Cook the pasta in a pot of well salted boiling water according to package instructions. Undercook by a minute so it remains al dente. Reserve a cup of pasta water towards the end.

Fry the pancetta in a large skillet in olive oil over medium heat until golden, about 5-6 minutes.

Add the garlic and let it sizzle for 30 seconds, moving it around so it doesn't burn.

Add the frozen peas and toss for another 30 seconds.

Add the cream and bring to a gentle simmer. Lower the heat if needed; it should never bubble aggressively.

Add the parmesan in 2-3 batches, stirring and allowing it to melt in between each addition.

Add the black pepper and lemon juice, mixing quickly.

Stir in the pasta and 1/4 cup pasta water. Let it gently bubble for 1-2 minutes until thickened.

Season to taste with salt and pepper, and add more pasta water if needed.

Finish with the arugula if using, then serve topped with extra parmesan and lemon zest.