Place an oven rack to the center position, preheat the oven to 325° F, ideally on the convection setting.
Break the eggs into a medium bowl and lightly scramble. Add the grated Pecorino Romano cheese, minced basil, salt, and pepper. Stir to combine and set aside.
In a 12-inch non-stick skillet, heat the olive oil over medium heat for a minute, then add the diced onion and sliced zucchini. Stir occasionally until the onions become translucent and the zucchini are just beginning to brown on one side.
Add the corn and stir to evenly distribute the vegetables int he skillet. Pour the egg mixture over it, making sure the liquid flows to the edges of the skillet and is level.
Cook over medium heat for about 5 minutes until the edges just begin to set.
Transfer the skillet to the pre-heated oven and continue cooking for about 15 minutes. The frittata will puff slightly, and it will be done when a clean butter knife is inserted in the center and comes out clean. Take care to not over bake it, it’s better to err to the soft and jiggly side than dry.
Carefully remove the skillet to a heat-safe surface and let set for about 5 minutes before slicing to serve. Remember to place a potholder or cloth over the skillet’s handle to let everyone know the handle is H.O.T.