Butterfly the chicken breast or pound it to an even half-inch thickness to ensure even cooking.
In a shallow bowl, whisk the egg until smooth. In a second shallow bowl, combine the almond flour, parmesan cheese, garlic powder, sea salt, and black pepper.
Dip the chicken into the egg wash, letting any excess drip off, then press firmly into the parmesan mixture until evenly coated on both sides.
Heat the olive oil in a non-stick skillet over medium heat. Add the chicken and cook for 5-6 minutes per side until the crust is golden brown and the internal temperature reaches 165 degrees Fahrenheit.
While the chicken is cooking, steam the broccoli florets in a steamer basket over boiling water for 4-5 minutes until tender-crisp.
Warm the marinara sauce in a small saucepan over low heat until simmering.
Plate the crispy chicken, spoon the warm marinara sauce over the top, and serve immediately with the steamed broccoli on the side.