Bring a pot of salted water to a boil and cook the brown rice spaghetti according to package directions until al dente.
While the pasta cooks, dice the chicken breast into bite-sized pieces and mince the garlic.
In a small bowl, whisk together the egg and grated parmesan cheese until well combined; set aside.
In a large skillet over medium heat, cook the pancetta until the fat has rendered and it becomes crispy.
Add the diced chicken to the skillet with the pancetta and sauté until cooked through and golden brown.
Stir in the minced garlic and cook for 30 seconds until fragrant, then season with sea salt and black pepper.
Reserve 2 tablespoons of the pasta cooking water, then drain the spaghetti.
Turn off the heat on the skillet and add the hot pasta and reserved water to the chicken and pancetta mixture.
Quickly pour the egg and cheese mixture over the pasta, tossing constantly for 1 minute to create a creamy sauce without scrambling the eggs.
Garnish with freshly chopped parsley and serve immediately.