Preheat your oven to 400°F (200°C) and ensure you have an oven-safe skillet ready.
Place the chicken breast between two sheets of parchment paper and pound with a meat mallet to an even half-inch thickness.
In a shallow bowl, whisk the egg until smooth. In a separate shallow bowl, combine the almond flour, parmesan cheese, garlic powder, oregano, sea salt, and black pepper.
Dip the chicken breast into the egg wash, allowing any excess to drip off, then press it firmly into the almond flour mixture until fully coated on both sides.
Heat the olive oil in the oven-safe skillet over medium-high heat. Once hot, sear the chicken for 2-3 minutes per side until the coating is golden and crisp.
Spread the marinara sauce evenly over the top of the seared chicken and place the mozzarella cheese slices directly onto the sauce.
Transfer the skillet to the preheated oven and bake for 8-10 minutes, or until the chicken reaches an internal temperature of 165°F and the cheese is melted and bubbly.
Remove from the oven and let the chicken rest for 2 minutes before garnishing with fresh torn basil and serving.