Cook the Pasta: Begin by cooking your pasta according to the package directions until al dente. Ensure to periodically check your pasta to avoid overcooking.

Sauté the Onions: In a large skillet, add a bit of water and set over medium heat. Add the diced onions and sauté until they become translucent. This process should take about 5 minutes.

Add Spinach: Once the onions are ready, add the fresh spinach to the skillet. Sauté the spinach with the onions, stirring frequently, until the spinach has wilted, and the raw spinach smell is no longer present. This step is crucial for developing the flavor.

Blend the Sauce: Transfer the sautéed spinach and onions into a high-speed blender. Add the garlic, cashews, nutritional yeast (if using), veggie broth, lemon juice, nutmeg, salt, and pepper. Blend on high until the mixture becomes very creamy and smooth. Taste and adjust seasonings as needed.

Combine Pasta and Sauce: Drain your cooked pasta well and return it to the pot. Pour the creamy spinach sauce over the pasta and toss gently until the pasta is evenly coated.

Serve: Your Vegan Spinach Pasta Sauce is now ready to be served. Enjoy this creamy, nutritious dish as is, or use it as a base for other side dishes.