Ingredients

• 2 tablespoons (1/4 stick) butter
• 2 tablespoons extra-virgin olive oil plus additional for drizzling
• 1/2 pound spring onions or green onions (dark green parts discarded); white parts cut into 1/4-inch-thick slices, pale green parts cut into 1/2-inch-thick slices
• 2 tablespoons minced shallot
• Coarse kosher salt
• 1/2 cup dry white wine
• 1/2 cup low-salt chicken broth
• 1 1/2 pounds asparagus, cut crosswise into 3/4-inch pieces
• 2 cups shelled fresh peas (from about 2 pounds peas in pods)
• 1 pound campanelle (trumpet-shaped pasta) or medium (about 1-inch) shell-shaped pasta
• 1 head of butter lettuce or Boston lettuce (about 6 ounces), cored, leaves cut into 3/4-inch-wide slices
• 1 cup finely grated Parmesan cheese plus additional for sprinkling
• 1/2 cup chopped fresh Italian parsley
• 4 ounces thinly sliced prosciutto, cut crosswise into 1/2-inch-wide strips

Instructions

1. Melt butter with 2 tablespoons oil in heavy large skillet over medium heat. Add onions and shallot. Sprinkle with coarse salt and pepper. Sauté until tender (do not brown), about 8 minutes. Add wine; increase heat to medium-high and simmer until liquid is reduced to glaze, about 3 minutes. Add broth and bring to simmer; set aside.
2. Cook asparagus in large pot of boiling salted water until just tender, 2 to 4 minutes, depending on thickness of asparagus. Using skimmer or slotted spoon, transfer to large bowl of ice water. Return water to boil. Add peas and cook until just tender, about 2 minutes. Using skimmer, transfer to bowl with asparagus. Drain vegetables.
3. Return water in pot to boil. Cook pasta until tender but still firm to bite, stirring occasionally. Drain, reserving 1 cup pasta cooking liquid.
4. Meanwhile, reheat onion mixture. Add lettuce and stir just until wilted, about 1 minute. Add drained asparagus and peas; stir until heated through.
5. Add pasta, 1 cup Parmesan cheese, and parsley to skillet with vegetables; toss, adding reserved pasta cooking liquid by 1/4 cupfuls if dry. Season with salt and pepper.
6. Transfer pasta to large shallow bowl. Sprinkle prosciutto over; drizzle with olive oil. Serve, passing more cheese alongside.