1. Prepart the vegetables: cut the corn kernels from the cobs and scrape the corn milk from the cobs. Stem the tomatoes and cut them into small cubes. Wash the okra and thinly slice it. Set the vegetables aside.
2. In a heavy skillet, melt the butter over medium-high heat. Add the onions and garlic and saute until wilted, about 5 minutes, stirring occasiionally. Add the corn, tomatoes, okra, and all remaining ingredients. Reduce heat to medium and cook, stirring frequently, for 10 minutes. Reduce heat to low, cover, and cook for 15 minutes more, stirring occasionally. Serve at once, garnished with additional parsley if desired.