Rinse the shrimp and pat dry; season with 1/2 teaspoon kosher salt and 1/4 teaspoon (adjust as desired) black pepper.
Heat 1 tablespoon olive oil in a large nonstick skillet over medium-high heat. Add the shrimp and cook 2 to 3 minutes, stirring occasionally, until opaque and just cooked through. Transfer shrimp to a plate and set aside.
Reduce heat to medium and add 1 tablespoon butter to the skillet. Sprinkle 2 tablespoons flour over the melted butter and cook 30 seconds, whisking, until fragrant and lightly browned.
Slowly whisk in 1 cup chicken broth, then 1 cup milk, a few tablespoons at a time, whisking to dissolve lumps. Stir in 1 teaspoon garlic powder, 1/2 teaspoon onion powder, and 1/8 teaspoon red pepper flakes. Bring the sauce to a gentle boil.
Add the package of ravioli to the simmering sauce in a single layer. Boil gently, stirring occasionally, until the ravioli are al dente, about 4 minutes (do not overcook).
Reduce heat to low, then stir in 1/2 cup finely grated Parmesan, 3/4 cup thawed peas, and the reserved shrimp. Heat just until everything is warmed through, about 30 seconds to 1 minute.
Remove from heat and sprinkle with 2 tablespoons chopped fresh parsley or basil. Serve immediately with extra red pepper flakes, salt, or pepper to taste if desired.