Bring a large pot of salted water to a rolling boil over high heat. Add your spaghetti and cook until al dente, typically around 8-10 minutes. Reserve ½ cup of the starchy pasta water before draining.

In a large skillet, melt the unsalted butter along with olive oil over medium heat. This will create a rich base for your sauce.

Add minced garlic and red pepper flakes into the skillet, stirring continuously for about 1 minute until garlic is fragrant and golden.

Incorporate the trimmed asparagus into the skillet, stirring to coat. Sauté for about 3-4 minutes, until tender-crisp and vibrant.

Now, add the peeled and deveined shrimp, seasoning with salt and pepper. Cook for 3-5 minutes until shrimp turn pink and opaque.

Carefully stir in the cooked spaghetti and reserved pasta water. Add lemon zest and juice, tossing to combine.

Remove from heat and sprinkle with parsley and grated Parmesan cheese. Serve immediately.