1
: In a large amount of boiling, salted water, cook pasta until just tender.
2
: While pasta cooks, in a separate saucepan, cook asparagus in boiling water until very tender. Drain and refresh under cold water. Drain well. Purée in food processor until coarsely chopped. Add evaporated milk, reserved asparagus water, olive oil, lemon zest, salt and pepper.
3
: Drain pasta and return to saucepan. Add asparagus sauce and heat pasta and sauce over medium heat until hot, about 5 minutes. Do not boil.
4
: Transfer to a serving dish. Toss with Parmesan.