In a large pot of salted boiling water, cook the fettuccine according to package instructions until al dente. Drain and set aside, reserving about ½ cup of the pasta cooking water.
In a large skillet over medium-high heat, melt 2 tablespoons of butter. Add the sliced chicken breasts, season with salt, pepper, Italian seasoning, and red pepper flakes. Cook for about 5-7 minutes or until the chicken is cooked through and browned. Remove the chicken from the skillet and set aside.
In the same skillet, melt the remaining 2 tablespoons of butter. Add minced garlic and sauté for about 30 seconds until fragrant (be careful not to burn).
Pour in the chicken broth and bring it to a simmer. Add the halved cherry tomatoes and cook for 3-4 minutes until the tomatoes begin to soften.
Return the cooked chicken to the skillet and add the drained pasta. Toss everything together, adding reserved pasta water as needed to reach desired creaminess.
Sprinkle in freshly grated Parmesan cheese, tossing until melted and evenly distributed throughout the pasta. Adjust seasoning with more salt and pepper if needed.
Garnish with freshly chopped parsley and additional Parmesan if desired.
Notes
Feel free to adjust the amount of red pepper flakes for desired heat.