In a large serving bowl, toss together the corn, apples, fennel, and onion. (Reserve 1 cup of the mixture for the Corn Puddings recipe.) Add the parsley and cumin and season with salt and pepper, to taste. In a small bowl, whisk together the vinegar, mustard, and oil. (Reserve 2 tablespoons of the vinaigrette for the Round 2 Salad recipe.) Add the dressing to the vegetables and toss well to coat.