Preheat your oven to 400°F.
Line a baking sheet with parchment paper. Peel and cube the sweet potato, then toss with paprika, cinnamon, salt, and pepper.
Roast the sweet potato cubes in the oven for about 20-25 minutes, stirring halfway through, until tender.
While the sweet potatoes roast, finely chop the pistachios in a food processor until reaching a coarse crumb texture.
Place the chicken breast between two sheets of plastic wrap and gently pound to an even thickness.
Season the chicken breast with salt and pepper. Brush one side lightly with the egg white.
Press the egg white-coated side of the chicken into the chopped pistachios to form a crust.
Heat a non-stick skillet over medium-high heat and add the chicken, crust side down first. Sear for 2-3 minutes until the crust is golden.
Flip the chicken and cook for an additional 2 minutes, ensuring the chicken is nearly cooked through.
Transfer the skillet to the oven (or place the chicken on a baking dish) and bake for an additional 8-10 minutes until the chicken reaches a safe internal temperature.
Serve the crispy pistachio-crusted chicken with a side of spiced roasted sweet potatoes.