Grouper with Cucumber Salad and Soy Mustard Dressing

Name: Grouper with Cucumber Salad and Soy-Mustard Dressing
Ingredients: 3 tablespoons soy sauce; 3 tablespoons rice vinegar; 1 tablespoon mirin; 1 tablespoon sake; 2 teaspoons whole-grain mustard; 3 garlic cloves, coarsely chopped; 1/2 cup plus 1 tablespoon vegetable oil; 1 medium seedless cucumber, peeled and halved crosswise; One 3-inch piece of carrot, peeled; One 3-inch piece of daikon, peeled; 1 medium shallot, thinly sliced crosswise; Four 6-ounce skinless grouper fillets; Salt and freshly ground pepper; 1 long red fresh chile, cut into long, fine strips; Toasted sesame seeds, cilantro leaves and finely chopped chives, for garnish