1. Ahead of time, cook the black beans as directed on the package, until they are soft. Set aside.
2. Soften the dried cornhusks in simmering water for about 20 minutes.
3. In a small saucepan, simmer ½ cup of the corn kernels in the milk for 5 minutes. Remove from heat and let cool.
4. Blend corn and milk mixture in a blender or food processor for about 2 minutes, or until creamy. Add to rest of corn, and mix well. Set aside.
5. Spray a large skillet with cooking spray, and add the zucchini, onion, and chili. Cover and cook over medium-low heat for 10 minutes, stirring occasionally.
6. While zucchini mixture is cooking, remove corn husks from hot water and pat dry. Line a 2-quart baking dish with husks, allowing excess length to extend over the sides of the dish. Spray husks with cooking spray to prevent them from sticking to the dish when baking.
7. To zucchini mixture, add the flour and next four ingredients, and stir well. Add corn and beans, and stir well. Cook, uncovered, over medium heat for 4 minutes, stirring frequently.
8. Spoon the mixture into the baking dish. Fold the free ends of the husks toward the center of the baking dish. Cover top of mixture with any extra husks, overlapping.
9. Bake at 320 °F for 25 minutes.

Note that provided nutrition values do not include the corn-husks.