Step 1

If using frozen peas, place 1 cup in the bowl of a food processor fitted with the blade attachment to thaw while you prepare the dumplings and asparagus, about 20 minutes. If using fresh peas, bring a small pot of water to a boil. Add 1 cup shelled fresh peas and blanch until bright green and crisp-tender, about 1 minute. Drain and immediately transfer them to an ice water bath. Drain again and transfer to the food processor.

Step 2

Arrange a rack in the middle of the oven and heat the oven to 425°F. Snap the woody ends off 1 pound asparagus, then cut the stalks crosswise on a slight diagonal into 2-inch pieces. Place in a 9x13-inch or other 3-quart baking dish. Drizzle with 2 tablespoons olive oil and season with 1/2 teaspoon of the kosher salt and 1/4 teaspoon of the black pepper. Toss to coat, then spread out in an even layer.

Step 3

Finely grate 2 ounces Pecorino Romano cheese (about 1 packed cup). Place half in a medium bowl and half in the food processor. Finely grate the zest of 1 small lemon into the medium bowl. Halve the lemon and squeeze the juice into the food processor (about 2 tablespoons).

Step 4

Add 15 to 16 ounces whole-milk ricotta cheese, 1 large egg, 1/2 teaspoon of the kosher salt, and the remaining 1/4 teaspoon black pepper to the medium bowl and stir to combine. Add 1/4 cup all-purpose flour and stir to just combine; do not overmix.

Step 5

Use a size 40 (1 1/2 tablespoon) cookie scoop or 2 spoons to drop 16 golf ball-size portions of the ricotta mixture into the prepared baking dish, spacing them about 1/2-inch apart.

Step 6

Bake until the tops of the dumplings are firm and the asparagus is tender, about 15 minutes. Meanwhile, smash and peel 1 small garlic clove, then add it to the food processor. Add 1/3 cup olive oil and the remaining 1/4 teaspoon kosher salt. Process, stopping to scrape down the sides of the bowl as needed, until the mixture comes together into a rough paste, about 30 seconds. Coarsely chop 1/3 cup pistachios.

Step 7

Divide the pea pesto among 4 shallow bowls and spread it out in a large, even circle with the back of a spoon. Divide the dumplings and asparagus among the 4 bowls, piling it on top of the pesto. Sprinkle with the pistachios.