Prepare the chicken: Slice the chicken breast into thin pieces so it cooks quickly and evenly. Season with salt and chicken seasoning, drizzle with olive oil, and toss to coat.
Cook the pasta: Bring a large pot of salted water to a boil. Cook the pasta according to the package directions until al dente. Drain and set aside.
Cook the chicken: Heat a large skillet over medium-high heat. Add the chicken and cook until golden brown and completely cooked through. Transfer the chicken to a plate and set aside.
In the same skillet, melt the butter. Add the chopped onion and cook until soft and translucent.
Add the diced tomatoes and cook for a few minutes, until they begin to soften and release their juices.
Pour in the cream and stir well. Bring the sauce to a gentle simmer, then add the cooked pasta and toss until evenly coated.
Serve: Slice the cooked chicken and arrange it over the creamy pasta. You can leave the chicken on top or mix it into the sauce. Garnish with fresh herbs and grated Parmesan, if desired, and serve immediately.
