Serves 10 as a first course, 6 as a main course
Active time: 1 hour
Start to finish: 1½ hours
First introduced at the starry Le Cirque in New York City in the 1970's, pasta primavera rapidly became one of the most popular pasta dishes in America. Don't let the long list of ingredients faze you; once you've done the prep work, it's easy to throw together. One of the nice things about this version is that it calls for dried morels, frozen peas (more consistently sweet and tender than "fresh" peas), and asparagus (for better or worse, practically seasonless these days), so you don't have to wait until spring to make it.
1 ounce dried morel mushrooms
1½ cups warm water
½ pound asparagus, trimmed and cut into 1-inch pieces
¼ pound green beans, preferably haricots verts, cut into 1-inch pieces
¾ cup frozen baby peas, thawed
4 tablespoons extra-virgin olive oil
2 teaspoons minced garlic
Rounded ½ teaspoon red pepper flakes
Salt and freshly ground black pepper
1½ pints grape tomatoes
1 tablespoon balsamic vinegar
3 tablespoons water
1 pound spaghettini
½ stick (4 tablespoons) unsalted butter
2/3 cup heavy cream
1 teaspoon finely grated lemon zest
1 cup finely grated Parmigiano-Reggiano (about 2 ounces)
¼ cup finely chopped fresh flat-leaf parsley
¼ cup finely chopped fresh basil
1/3 cup (1½ ounces) pine nuts, lightly toasted
Optional garnish: Parmigiano-Reggiano shavings
Prepare the vegetables: Soak morels in warm water in a small bowl for 30 minutes.
Lift mushrooms out of water and squeeze excess liquid back into bowl. Pour soaking liquid through a sieve lined with a dampened paper towel into a small bowl; reserve. Rinse morels thoroughly to remove grit, then squeeze dry. Cut off and discard any tough stems. Halve small morels lengthwise and quarter larger ones.
Add asparagus and beans to a 6- to 8-quart pot of boiling salted water (1 tablespoon salt per every 4 quarts water) and cook, uncovered, for 3 minutes. Add peas and cook until beans and asparagus are just tender, 1 to 2 minutes more. Immediately transfer vegetables with a large slotted spoon to a bowl of ice and cold water to stop the cooking; reserve pot of water for cooking pasta. Drain cooled vegetables.
Heat 2 tablespoons oil in a 10- to 12-inch heavy skillet over moderately low heat. Add 1 tablespoon garlic and rounded ¼ teaspoon red pepper flakes and cook, stirring, just until garlic is fragrant, about 1 minute. Add drained vegetables and salt and pepper to taste and cook, stirring, for 2 minutes. Transfer to a bowl; set skillet aside.
Cook the tomatoes: Cut half of tomatoes into quarters and halve remainder lengthwise, keeping quarters and halves separate. Heat remaining 2 tablespoons oil in same skillet over moderately low heat. Add remaining 1 teaspoon garlic and remaining rounded ¼ teaspoon red pepper flakes and cook, stirring, just until garlic is fragrant, about 1 minute. Add quartered tomatoes, with salt and pepper to taste, and simmer, stirring occasionally, until tomatoes are softened, about 3 minutes. Add halved tomatoes, vinegar, and water and simmer, stirring occasionally, until sauce is thickened and halved tomatoes are softened, 3 to 4 minutes. Remove from heat and keep warm, covered.
Cook the spaghettini: Return pot of water to boil and cook spaghettini until al dente; drain in a colander.
Immediately add butter, cream, zest, and morels to (empty) pasta pot, bring to a simmer, and simmer gently, uncovered, for 2 minutes. Stir in cheese, then add pasta, tossing to coat and adding as much of reserved morel soaking liquid as necessary (½ to 2/3 cup) to keep pasta well coated. Add green vegetables, parsley, basil, pine nuts, and salt and pepper to taste and toss gently to combine.
Serve pasta topped with tomatoes and, if desired, Parmigiano-Reggiano shavings.