Step 1: Prepare the Spinach
Place the fresh spinach leaves in a large colander set in the sink. You’ll be draining the pasta over the spinach later, which will naturally wilt the leaves without overcooking them.

Step 2: Cook the Spaghetti
Bring a large pot of salted water to a boil. Add the spaghetti and cook according to the package directions until al dente (usually around 8-10 minutes). Once cooked, drain the pasta directly over the spinach in the colander. This clever method helps wilt the spinach while ensuring it retains its vibrant green color and texture. Set the drained pasta and spinach aside.

Step 3: Make the Sauce
In a large skillet, heat 1 tablespoon of the reserved oil from the sun-dried tomatoes over medium heat. Add the finely chopped red onion and sun-dried tomatoes to the skillet and cook, stirring occasionally, for about 3 minutes, until the onion becomes translucent and the tomatoes soften.

Next, stir in the minced garlic, crushed red pepper flakes, salt, and pepper. Sauté for an additional minute, just until the garlic becomes fragrant and slightly golden, taking care not to burn it.

Step 4: Combine Ingredients for the Sauce
Increase the heat to medium-high and pour in the vegetable or chicken broth. Cook the mixture for about 2-3 minutes, allowing the liquid to reduce by half. This step concentrates the flavors and thickens the sauce.

Once the broth has reduced, reduce the heat to low and stir in the sour cream and grated Parmesan cheese. Mix until everything is smooth and well combined. Finish the sauce by adding 2 tablespoons of butter, stirring until melted and incorporated. This gives the sauce a silky, rich texture.

Step 5: Toss Everything Together
Now it’s time to bring the whole dish together. Add the cooked spaghetti and wilted spinach to the skillet with the sauce. Toss everything together gently to ensure the pasta is evenly coated with the creamy sun-dried tomato sauce. Be sure to scrape the bottom of the skillet to get all the flavors mixed in well.

If the sauce seems too thick, you can add a splash of pasta water to reach your desired consistency