Bring salted water to a boil and cook pasta until al dente
Drain pasta and reserve a small amount of cooking water
Heat olive oil in a skillet over medium heat
Add sliced chicken and cook until lightly golden
Add garlic and sauté briefly
Add spinach and cook until wilted
Add cooked pasta to the skillet
Stir in lemon juice and Parmesan cheese
Add a splash of pasta water if needed to loosen the sauce
Season with salt and pepper before serving