Fill a large pot with lightly salted water and bring to a rolling boil. Stir in the fettuccine, bring back to a boil, and cook pasta over medium heat until cooked through but still firm to the bite, about 8 minutes.
While fettuccini is boiling, place asparagus and peas into a steamer insert and place insert over the pot of fettuccine. Steam vegetables until tender, 6 to 8 minutes. Remove steamer insert and drain fettuccine.
Combine fettuccine, asparagus, peas, basil, mint, parsley, feta cheese, scallions, and olive oil together in a large bowl. Season with salt and pepper.
