Prep and cook the vegetables. Snap off and discard the woody bases from the asparagus, then cut the spears into 2-inch pieces.
In a large saucepan, cook the asparagus and thawed peas in a small amount of boiling, lightly salted water for 3 to 5 minutes until tender.
Drain thoroughly.
Make the pesto base.
In a food processor or blender, combine half of the cooked asparagus and peas, the Parmesan cheese, half of the toasted pine nuts, lemon peel, garlic, salt, and pepper.
Cover and pulse until a paste forms, scraping down the sides of the container as needed.
Finish the pesto. With the machine running on low, slowly drizzle in the olive oil and blend until the mixture is smooth and creamy, like soft butter.
Set aside.
Cook the pasta.
In a large pot, cook the fettuccine in boiling, salted water according to package directions.
Drain well.
Assemble and serve. Return the hot, drained pasta to the pot.
Add the prepared pesto and toss to coat everything evenly.
Serve immediately, topped with the remaining cooked asparagus and peas, and sprinkle with the rest of the toasted pine nuts.
Reserve about a cup of the starchy pasta water before draining. It's liquid gold for thinning the pesto to the perfect consistency and helping it cling beautifully to the fettuccine.
