Begin by bringing a large pot of salted water to a boil. Add spaghetti and cook it according to the package instructions until al dente, typically about 8-10 minutes. Once cooked, drain the pasta well and toss it immediately with butter and freshly grated parmesan cheese until fully coated. Set aside while preparing the chicken and sauce.

In a large skillet, over medium heat, add chopped bacon pieces and cook until they turn crispy and golden brown, about 5-7 minutes. Stir occasionally to ensure even cooking, then remove the bacon with a slotted spoon and set it aside, leaving about 1-2 tablespoons of the rendered fat in the skillet.

While the bacon cooks, slice the chicken breasts into thin medallions for quicker cooking. Season both sides generously with garlic powder, salt, and pepper. Dredge each piece in flour to create a light coating, shaking off any excess.

In the same skillet with the leftover bacon fat, increase the heat to medium-high. Add the floured chicken pieces in a single layer, cook for about 4-5 minutes on each side until golden brown and cooked through. Transfer the chicken to a plate and cover loosely with foil to keep warm.

With the skillet still on medium-high heat, add 2 tablespoons of butter. Once melted, add the sliced cremini mushrooms along with Italian seasoning, and sauté for about 5-6 minutes until golden brown. Add the minced garlic and continue to cook for an additional minute until fragrant.

Pour in the Riesling, using a wooden spoon to scrape up the brown bits stuck to the bottom of the skillet. Let the mixture simmer for about 2-3 minutes, allowing the wine to reduce by half.

Lower the heat to medium, stir in the heavy cream until well combined. Return the sautéed chicken and crispy bacon to the skillet, and let everything simmer together for about 5 minutes.

Taste the sauce and adjust seasoning with additional salt and pepper if needed. Remove the skillet from heat. Serve the Elegant Sautéed Chicken in Riesling Sauce immediately over the tossed spaghetti, garnishing with extra parmesan and fresh herbs if desired.