Creamy Lemon Asparagus Pasta

Boil the pasta according to the package instructions. Add the asparagus to the boiling water 4 minutes before the pasta is done, and add the peas 2 minutes before draining. Before draining, reserve 1/4 cup of the starchy cooking water.
Prepare the Sauce:

In a large non-stick skillet, heat the oil and butter over medium-high heat. Add the sliced mushrooms and onion, and cook for 5 minutes until softened.
Add the garlic and cook for another 30 seconds until fragrant.
Stir in the flour and cook for another 30 seconds to create a roux.
Make it Creamy:

Slowly stream in the milk while stirring constantly, then bring the sauce to a simmer on low heat for 3-5 minutes until it thickens slightly.
Stir in the spinach and salt, cooking until the spinach wilts.
Combine Pasta and Sauce:

Pour the sauce over the cooked pasta, asparagus, and peas. Add the reserved starchy cooking water to the skillet, along with the lemon juice and zest. Stir everything together until well combined.
Serve and Garnish:

Plate the pasta and garnish with freshly grated Parmigiano Reggiano and chopped parsley for a touch of flavor and color.
Serving and Storage Tips