Ingredients:

• 12 ounces spaghetti
• 3 tablespoons olive oil
• 1 yellow onion, diced
• 1 pound medium-large uncooked shrimp (21/25 per pound)
• 1 bunch medium-sized asparagus, tough ends removed, cut into 1-inch pieces
• 4 cloves garlic, minced
• 1/2 teaspoon kosher salt, plus more to taste
• 1/4 teaspoon freshly ground black pepper, plus more to taste
• 1/2 cup dry white wine
• 3 tablespoons unsalted butter, divided
• 1 lemon, juiced
• 1/4 cup Parmesan, grated
• 4 teaspoons flat-leave parsley, chopped
• 4 lemon wedges