Skillet Tamale Pie

Name: Skillet Tamale Pie
Ingredients: safflower oil; 1/2 onion; 1 jalapeno, minced; 1 tablespoon chili powder; 2 clove garlic; 1 teaspoon dried oregano; 2 cups cooked pinto beans; 1 14.5 ounce can diced tomatoes; 1 cup frozen corn, thawed; 2 3/4 cups water; 3/4 cup polenta; 2 tablespoons butter or oil; Salt to taste