Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper.
Place the chicken breast between two pieces of plastic wrap and pound it to an even half-inch thickness for uniform cooking.
In a shallow bowl, whisk the egg white until slightly frothy to create a binder for the breading.
In a separate shallow dish, combine the almond flour, parmesan cheese, oregano, garlic powder, sea salt, and black pepper.
Dip the chicken breast into the egg white, then dredge it in the almond flour mixture, pressing firmly to adhere the coating to all sides.
Heat the avocado oil in a non-stick oven-safe skillet over medium-high heat and sear the chicken for 3 minutes per side until golden brown.
Spread the marinara sauce over the chicken and top with the shredded mozzarella cheese.
Transfer the skillet to the oven and bake for 5 to 7 minutes until the cheese is bubbly and the chicken is cooked through.
While the chicken bakes, lightly sauté the zucchini noodles in a separate pan for 2 minutes until tender-crisp, then serve the chicken on top garnished with fresh parsley.