Preheat the oven to 350 degrees. In a small bowl, combine, flour, cornmeal, baking powder, and coriander. Blend well, and set aside. In a large skillet, heat oil over medium heat. Add the onion and garlic, and cook for 1 minute. Add the zucchini, jalapeno, salt, and pepper. Cook, stirring for 2 minutes. Remove from heat. In a large bowl, beat the eggs until blended. Mix in the milk, sour cream, and cheese. Add the reserved dry ingredients, and blend well. Add the zucchini mixture and mix well. Scrape into a buttered 9-inch square dish. Bake for 40 minutes.