Cook the fettuccine pasta according to package instructions until al dente. While the fettuccine is cooking, prepare the sauce. Whisk together an egg, egg yolks, Parmesan cheese, salt, and pepper in a bowl. Set aside.
In a large skillet, cook the bacon for 3-4 minutes on each side or until cooked through.
Then, add minced garlic and cook for 1 minute until just fragrant.
Add the cooked chicken and cook for a few minutes more until the chicken pieces are warmed up. Reduce the heat to low.
When the fettuccine pasta is cooked until al dente, reserve ½ cup water and drain the remaining water. Transfer the fettuccine to the skillet with the bacon and chicken. Pour the egg mixture over the fettuccine and quickly and gently toss to combine. Then, add 2 tbsp of reserved pasta water and stir until you get a nice moist, and creamy sauce. You may need more than 2 tbsp of reserved pasta water.
Top with more cheese, freshly ground pepper, or chopped parsley.