Rinse the 1 pound shrimp and pat dry with paper towels. Heat 1 tablespoon extra-virgin olive oil in a large nonstick skillet over medium-high heat until shimmering. Add the shrimp, then sprinkle with ½ teaspoon kosher salt and ¼ teaspoon ground black pepper. Cook 2 to 3 minutes, stirring occasionally, until the shrimp are opaque and just cooked through. Transfer the shrimp to a plate and set aside.

Reduce the heat to medium. Add 1 tablespoon unsalted butter to the skillet and let it melt. Sprinkle 2 tablespoons all-purpose flour over the melted butter and cook 30 seconds, whisking constantly, until the flour is lightly browned and aromatic.

Slowly whisk in 1 cup low-sodium chicken broth, a few tablespoons at a time, then whisk in 1 cup nonfat milk the same way, scraping the bottom of the pan and breaking up any lumps. Stir in 1 teaspoon garlic powder, ½ teaspoon onion powder, and 1/8 teaspoon red pepper flakes. Bring the sauce to a gentle boil.

Add 1 package store-bought ravioli to the simmering sauce in a single layer. Cook, stirring occasionally, until the ravioli are al dente according to the package instructions. Reduce the heat to low.

Stir in ½ cup finely grated Parmesan cheese (or ¾ cup shredded), ¾ cup thawed frozen green peas, and the reserved shrimp. Stir just until everything is warmed through, about 30 seconds to 1 minute. Remove from heat.

Serve immediately, sprinkled with 2 tablespoons chopped fresh parsley or basil.