Start by seasoning the all-purpose flour with salt and pepper. Dredge each pounded chicken breast in the flour, shaking off any excess.
In a large skillet, heat the olive oil and butter over medium heat. Once hot, add the floured chicken breasts to the skillet. Cook for about 4-5 minutes on each side until golden brown and cooked through. Remove the chicken and set it aside on a plate.
In the same skillet, add the minced garlic and onion powder, sautéing for about one minute until fragrant. Pour in the chicken stock and crushed tomatoes, stirring to combine. Add the sugar and freshly chopped parsley, then let the sauce simmer for about 10 minutes.
Return the cooked chicken to the skillet, spooning some of the sauce over the top. Sprinkle the grated Parmesan cheese evenly over the chicken. Cover the skillet and let it cook for an additional 5 minutes.
While the chicken is finishing up, bring a large pot of salted water to a boil. Add the linguine and cook according to the package instructions until al dente. Drain and set aside.
To serve, place a generous helping of linguine on each plate, topped with a piece of Chicken Parmigiana and a ladle of sauce. Garnish with extra parsley for a fresh touch. Enjoy your delicious meal!