In a large frying pan or skillet over medium heat, warm up the chicken cacciatore. When the sauce is hot and the chicken warmed-through, use forks to pull the chicken meat off any bones, and tongs to remove the bones from the sauce. Reduce the heat to low and leave to simmer.
Bring a large pot of water to a rolling boil, add a teaspoon of salt, then add the spaghetti to the boiling salted water, give it a stir to ensure it’s all separated, and cook it for a minute less than the packet instructions direct until it’s almost al dente; no longer, as the spaghetti will continue to expand when added to the sauce.
When the spaghetti is cooked, reserve a metric cup of cooking water before draining the spaghetti into a colander.
Transfer the spaghetti to the sauce, add half a cup of pasta water, and stir it well so the spaghetti is completely covered in sauce, adding a little more cooking water and a tablespoon of extra virgin olive oil for an even more luscious sauce.
Distribute the spaghetti between the bowls, ladle on any remaining chicken cacciatore sauce in the bottom of the pan, sprinkle on the grated Parmigiano Reggiano, garnish with fresh basil leaves, and serve immediately with crusty bread.