Pat the shrimp thoroughly dry with paper towels and season with kosher salt and black pepper.
Heat 1 tablespoon of the olive oil in a large skillet with a lid over medium-high heat. Add the shrimp in a single layer and cook for about 1½ to 2 minutes on the first side. Turn and cook for another 1 to 2 minutes, just until the shrimp are opaque and cooked through. Transfer to a plate and set aside.
Reduce the heat to medium and add the remaining 2 tablespoons olive oil. Add the shallot, garlic, and red pepper flakes. Cook for about 1 minute, stirring frequently, until fragrant but not browned.
Stir in the chicken broth, white wine, parsley, and orzo. Scrape the bottom of the skillet to loosen any flavorful browned bits left from the shrimp. Bring to a boil.
Reduce the heat to medium-low, cover, and cook for 2 minutes.
Stir in the zucchini, cover again, and cook for another 6 to 7 minutes, stirring once or twice, until the orzo is tender and most of the liquid has been absorbed. There should still be a little creamy liquid in the pan; if the orzo becomes dry before it is tender, add a small splash of broth.
Remove the skillet from the heat. Stir in the Pecorino Romano, Parmesan, and lemon zest until the cheese melts and the orzo becomes creamy.
Stir in the basil, then gently fold the cooked shrimp back into the orzo. Let them sit in the hot pasta for about 30 seconds to warm through.
Taste and adjust with kosher salt, black pepper, and fresh lemon juice as needed. Serve immediately with extra Pecorino and Parmesan.
Notes
Erren's Top Tips
Pat the shrimp completely dry before cooking so they sear instead of steam.
Add the zucchini halfway through cooking so it keeps some texture.
Grate the cheese yourself for the smoothest, creamiest sauce.
Taste before adding more salt—the Pecorino adds plenty of seasoning.
Finish with fresh lemon juice right before serving to brighten the whole dish.
Variations & Add-Ins
Stir in fresh baby spinach during the last minute of cooking.
Add halved cherry tomatoes for extra sweetness.
Replace zucchini with asparagus or broccoli florets.
Use scallops instead of shrimp.
Add sautéed mushrooms for a heartier meal.
Finish with toasted pine nuts for crunch.
Storage & Freezing
Refrigerator: Store leftovers in an airtight container for up to 3 days.Reheating: Warm gently over low heat with a splash of chicken broth to loosen the sauce.Freezing: The orzo softens after freezing, so this recipe is best enjoyed fresh. If freezing, store for up to 2 months and thaw overnight before reheating gently.