Heat oven to 200ºF. Bring a large pot of water to a rolling boil.

While you wait for the water to boil, prepare the chicken. In a shallow dish, combine the flour, paprika, salt, and pepper. In a clean bowl, beat the egg with 1 tablespoon water. Dip the chicken into the egg, then dredge in flour.

Heat 1 tablespoon of olive oil in a large nonstick skillet set oven medium-high heat. Add the chicken and cook for 2 minutes on each side, or until golden brown and cooked through. Sprinkle with half the lemon juice and transfer to the oven to keep warm.

Add the noodles to the boiling water and cook for 10 minutes.

While the noodles cook, heat the remaining oil over medium heat. Add the onion and cook 2 minutes, or until softened. Add the shredded Brussels sprouts and cook 5 minutes, or until they begin to turn golden brown on the edges. Drain the noodles and add to the pan with the vegetables. Sprinkle with the remaining lemon juice and stir well to combine.

Top the noodles with the chicken. Garnish with parsley, if desired.