Fill a large pot with water, add a generous pinch of salt, and bring it to a rolling boil over high heat. Once boiling, add the spaghetti alla chitarra and cook according to package instructions until al dente, usually about 8-10 minutes. Save one cup of pasta water before draining.

While the pasta is cooking, heat a large sauté pan over medium heat and drizzle in the extra virgin olive oil. Add the chopped guanciale and sauté for approximately 5-7 minutes until crispy and golden.

In a separate mixing bowl, combine the fresh egg yolks, grated Parmigiano Reggiano, crushed Calabrian chili, and a dollop of tomato paste. Whisk until smooth.

Once the spaghetti is cooked al dente, drain it well and transfer it to the sauté pan with the crispy guanciale. Toss thoroughly in the guanciale and oil for 1-2 minutes on low heat.

Remove the sauté pan from direct heat and rapidly pour the egg mixture over the pasta while tossing vigorously to create a creamy sauce. Adjust thickness with reserved pasta water if needed.

Toss in the freshly chopped Italian parsley before serving to enhance flavor and aesthetic.

Serve immediately in wide, shallow bowls and garnish with chives and extra grated Parmigiano Reggiano.