Crispy Cod with Lentils

Name: Crispy Cod with Lentils
Ingredients: 2 carrots, halved lengthwise and sliced crosswise; 1 large or 2 small leeks (white and light green parts only), halved lengthwise and sliced crosswise; Kosher salt; 1 8-ounce package precooked lentils (about 1 1/2 cups); 2 tablespoons plus 1 teaspoon red wine vinegar; 1/4 cup plus 1 teaspoon extra-virgin olive oil; Freshly ground pepper; 1 1/2-pound piece center-cut skinless cod fillet, cut into 4 pieces; 1 tablespoon Dijon mustard; 1 clove garlic, finely grated; 3 tablespoons breadcrumbs; 1 tablespoon finely chopped fresh parsley; 4 cups baby arugula (about 2 1/2 ounces)