In a large pot of salted boiling water, cook the fettuccine until al dente according to package instructions. Reserve 1 cup of pasta water and drain the rest. Set aside.
In a large skillet, heat olive oil over medium heat. Season the sliced chicken breasts with salt and pepper. Add the chicken to the skillet and sauté until golden brown and cooked through, about 6-8 minutes. Remove chicken from skillet and set aside.
In the same skillet, add minced garlic and sauté for about 30 seconds until fragrant. Pour in the chicken broth, scraping the bottom of the pan to deglaze. Bring to a simmer.
Stir in the heavy cream, lemon zest, and lemon juice. Allow the mixture to simmer gently for 2-3 minutes, stirring occasionally until it slightly thickens.
Add the halved cherry tomatoes and baby spinach to the skillet, cooking until the spinach wilts. Return the cooked chicken to the skillet and stir to combine everything.
Add the drained fettuccine to the skillet and toss everything together. If the mixture seems too thick, gradually add reserved pasta water until you reach your desired consistency.
Stir in grated Parmesan cheese and season with additional salt and pepper to taste. Allow it to heat through for another minute.
Remove from heat and garnish with fresh chopped parsley. Serve immediately and enjoy your creamy lemon chicken pasta!
Notes
Reserve pasta water to adjust consistency if needed.