Set a rack in the middle of the oven and heat the oven to 400°F.

Put a 10-inch oven-safe skillet on the stove and add the olive oil. Warm the skillet over medium heat for about 1 minute.

Add the chopped onion to the skillet with 1/2 teaspoon of the salt. Cook for 4 minutes, stirring now and then, until the onion starts to soften.

Add the chopped red bell pepper to the skillet. Cook for 5 minutes, stirring a few times, until the pepper softens and the onion looks glossy.

Add the chopped garlic and the ground cumin to the skillet. Stir for 30 seconds, just until the garlic smells fragrant.

Add the drained pinto beans, frozen corn, and salsa to the skillet. Stir well so the beans are coated and the filling looks evenly saucy.

Bring the filling to a gentle bubble over medium heat. Cook for 4 to 5 minutes, stirring once or twice, until the sauce thickens slightly and is no longer watery around the edges.

Turn off the heat under the skillet. Stir in 1/2 cup of the shredded cheddar until it starts to melt into the filling.

Put the cornmeal, flour, baking powder, and the remaining 1 teaspoon salt in a medium bowl. Whisk until the dry ingredients are evenly mixed.

Crack the egg into a small bowl. Add the milk and whisk until the egg is fully broken up and blended into the milk.

Pour the milk mixture into the bowl of dry ingredients. Stir with a spoon just until a thick batter forms and you no longer see dry flour.

Spoon the batter over the bean filling in the skillet. Spread it gently into an even layer with the back of the spoon.