Cook corn, bell pepper, and 1/2 cup chopped green onions in a Dutch oven over medium-high heat 2 minutes. Add chicken broth and evaporated milk. Bring to a boil; cover, reduce heat, and simmer 15 minutes, stirring occasionally.
Puree 1 cup of corn mixture in an electric blender until smooth; return mixture to Dutch oven. Stir in cheese, salt, and ground red pepper.
To serve, ladle 1 1/4 cups soup into each of 4 individual serving bowls. Sprinkle each with 1 tablespoon green onions and black pepper.