Bring a large pot of salted water to boil and add pasta according to package directions. Cook until al dente—about 10-12 minutes. Reserve 1 cup of pasta water before draining, then set aside.
While pasta cooks, heat olive oil in a large skillet over medium-high heat. Add diced chicken breast and cook until golden and cooked through, approximately 6-8 minutes. Season with salt and pepper, then transfer to a plate.
In the same skillet, melt butter and sauté minced garlic for 45 seconds until fragrant. Add Italian seasoning and stir constantly to prevent burning.
Pour in chicken broth and bring to a simmer for 2 minutes. This weeknight pasta recipe comes together when you add the heavy cream slowly, stirring constantly to prevent curdling.
Reduce heat to medium and add grated parmesan cheese in handfuls, stirring until completely melted and smooth. This takes about 2-3 minutes. Return cooked chicken to the skillet.
Add fresh spinach and sun-dried tomatoes, stirring until the spinach wilts completely—about 1-2 minutes. The residual heat ensures perfectly tender greens without overcooking.
Combine drained pasta with the cream sauce, tossing gently to coat all strands evenly. Add reserved pasta water a splash at a time until the sauce reaches your desired consistency.
Finish with fresh chopped basil and serve immediately while hot and creamy.