Heat 1 tablespoon olive oil in a 10-inch nonstick skillet over medium heat (or coat with cooking spray). Add onion and cook, often stirring, until onion wilts, for about 4 minutes. Add garlic and cook 1 minute longer. Crumble ground turkey into the skillet and continue to cook over medium heat, stirring to break up any lumps of turkey until onion is lightly browned and the meat is no longer pink for about 5 minutes.

Add the chile peppers, oregano, pinto beans, tomatoes, corn, 1/2 teaspoon of the salt (if using), and 1/4 teaspoon of the pepper. Reduce heat to medium and simmer, uncovered, occasionally stirring, until thickened, for about 15 minutes.

Preheat oven to 350°F / 175°C (180°C fan-forced). Lightly coat a 9-inch square (23cm) baking dish or casserole with cooking spray. Transfer turkey mixture to the casserole and smooth the top. Set aside.

In a medium saucepan, bring 1 1/2 cups (355ml) water to a simmer over medium heat. Whisking all of the time, gradually add the cornmeal, ground cumin, and the remaining 1/4 teaspoon salt and 1/4 teaspoon pepper. Cook, constantly stirring, until cornmeal is quite thick, 3 to 5 minutes.

Spoon the cornmeal mixture on top of the turkey mixture and spread evenly over the top, sealing to the edges of the dish. Sprinkle the cheese evenly over the cornmeal topping. Bake at 350°F / 175°C for 30 to 35 minutes, or until the cornmeal topping is set and firm in the centre and the cheese is melted and lightly golden. Let rest 10 minutes before cutting. Serve hot, sprinkled with green onions.