Heat olive oil in a large saucepan over medium heat.

Add onion and cook until softened, about 5-6 minutes.

Add garlic and cumin, cook while stirring until fragrant, about 2 minutes.

Add green chiles, black beans, diced tomatoes with juice, water, and salt to the pan.

Bring the mixture to a boil, then reduce heat to medium-low.

Simmer partially covered, until slightly thickened, about 20 minutes.

Puree about 2 cups of the stew using a blender or food processor.

Return the puree to the pan and add frozen corn.

Simmer until the corn is heated through, about 5 minutes.

Serve hot.