Steam the corn until tender, 4 to 5 minutes. When it is cool enough to handle, cut the kernels from the cobs.
Combine the corn, arugula,lettuce, herbs and Parmesan in a salad bowl. In a small bowl or measuring cup, whisk together the sherry vinegar, balsamic vinegar, Dijon mustard, garlic, salt, pepper and olive oil.
Just before serving, toss the salad with the dressing. Garnish with the tomato wedges and serve.
Advance preparation: You can prepare the salad ingredients and dressing several hours before tossing the salad.