Before you start, get everything ready: trim your asparagus and cut into 1-inch pieces. Peel and devein your shrimp. Mince the garlic, zest the lemon, and squeeze out its juice. Chop your fresh parsley.

Bring a large pot of salted water to a rolling boil. Add the angel hair pasta and cook according to package directions, usually about 3-4 minutes. During the last 2 minutes of cooking, add the asparagus to the boiling water with the pasta. Before draining, reserve 1 cup of the starchy pasta water. Drain the pasta and asparagus and set aside.

While the pasta cooks, heat 1 tablespoon of olive oil in a large skillet (at least 12-inch) over medium-high heat. Add the shrimp in a single layer and cook for 1.5-2 minutes per side, until they turn pink and opaque. Don't overcrowd the pan; cook in batches if necessary. Remove the cooked shrimp from the skillet and set aside.

Reduce the heat to medium. Add the remaining 1 tablespoon of olive oil and the butter to the same skillet. Once the butter is melted, add the minced garlic and red pepper flakes (if using). Sauté for about 1 minute until the garlic is fragrant, being careful not to burn it.

Pour in the white wine (or broth) and lemon juice. Bring the mixture to a gentle simmer, scraping up any browned bits from the bottom of the pan with a wooden spoon. Stir in the lemon zest. Let it simmer for 1-2 minutes to allow the flavors to meld and the liquid to slightly reduce.

Add the cooked pasta, asparagus, and sautéed shrimp back into the skillet with the sauce. Toss gently to coat everything. If the sauce seems too thick, add a splash or two of the reserved pasta water until it reaches your desired consistency.

Stir in the fresh chopped parsley. Season with additional salt and pepper to taste. Serve immediately, garnished with a generous sprinkle of freshly grated Parmesan cheese.