Butterfly the chicken breast or pound it to an even thickness for uniform cooking.
In a shallow bowl, whisk the egg until smooth. In a separate shallow dish, combine almond flour, parmesan, oregano, garlic powder, salt, and pepper.
Dip the chicken into the egg wash, allowing any excess to drip off, then dredge in the parmesan mixture, pressing firmly to ensure a thick crust.
Heat the olive oil in a large non-stick skillet over medium heat.
Place the chicken in the skillet and cook for 5-6 minutes per side until the crust is golden brown and the internal temperature reaches 165°F.
While the chicken rests, warm the marinara sauce in a small saucepan over low heat.
Quickly sauté the zucchini in the same skillet used for the chicken for 2-3 minutes until just tender-crisp.
Serve the chicken over the zucchini and top with the warm marinara sauce.