Spaghetti and Spinach with Sun-Dried Tomato Cream Sauce

Cook the spaghetti according to package instructions in a large pot of salted boiling water until al dente. Drain the spaghetti, reserving about 1/2 cup of the pasta cooking water.
In a large skillet, melt the butter over medium heat. Add the chopped onion and minced garlic, sauté until softened and fragrant, about 2-3 minutes.
Stir in the chopped sun-dried tomatoes and cook for another 1-2 minutes.
Pour in the vegetable or chicken broth and bring to a simmer. Let it cook for about 5 minutes to allow the flavors to meld together.
Reduce the heat to low and add the sour cream to the skillet. Stir until well combined and heated through.
Add the cooked spaghetti and baby spinach to the skillet. Toss gently until the spinach wilts and the spaghetti is well coated with the sauce. If the sauce seems too thick, add some of the reserved pasta cooking water to thin it out.
Season with salt, ground black pepper, and red pepper flakes (if using), to taste. Mix well.
Sprinkle grated Parmesan cheese over the spaghetti and spinach mixture. Stir until the cheese is melted and incorporated into the sauce.
Serve the spaghetti and spinach with sun-dried tomato cream sauce hot, garnished with extra Parmesan cheese if desired. Enjoy your flavorful and creamy pasta dish!