Bring a large saucepan of salted water to the boil for the pasta. At the same time bring a second large saucepan of salted water to the boil for the poached eggs. Add the white wine vinegar to the poaching liquid and stir. Once the poaching liquid is up to heat leave at a gentle simmer.

Heat a large frying pan over medium high heat and add the pancetta. Fry until golden  brown and crispy. Set aside on paper towel to drain. Leave the rendered fat in the frying pan. Add the spaghetti to the salted water, following the spaghetti cooking instructions, cooking until al dente (reduce the cooking time by 1-2 minutes). At the same time add the chicken broth to the remaining pancetta fat and reduce down by a third. Once the chicken broth is reduced add the parsley, arugula and the pepper and salt. Then add the drained spaghetti and increase the heat to high, combining the pasta with the sauce. Cook for a further two minutes. Remove from the heat and add the two cheeses, stirring constantly until fully incorporated.

Crack each of the four eggs, one at a time into the poaching liquid and cook until the whites combine and set. This should take two or three minutes. As the eggs poach, distribute the pasta into four serving bowls. Add a poached egg to the top of each dish and then finish with a crack of black pepper. Serve (for maximum effect combine the egg with the pasta immediately).