Bring a pot of salted water to a boil and cook the spaghetti until al dente.
While pasta cooks, dice the chicken and pancetta into small pieces.
In a skillet over medium heat, sauté the pancetta until the fat renders and it becomes crispy.
Add the diced chicken and minced garlic to the skillet, cooking until the chicken is golden and cooked through.
In a small bowl, whisk the egg and parmesan cheese together until well combined.
Reserve 0.25 cup of pasta water, then drain the spaghetti.
Turn off the heat on the skillet and add the hot pasta, tossing with the chicken and pancetta.
Quickly pour in the egg mixture and reserved pasta water, stirring constantly to create a creamy sauce without scrambling the eggs.
Season with sea salt and black pepper, then garnish with fresh parsley.