Fish Tacos

Ingredients

• 1 1/2 pounds scrod fillets or other firm-fleshed white fish fillets, cooked, drained well, and flaked
• 1/2 cup Kalamata or other brine-cured black olives, pitted and chopped
• 1 cup seeded and chopped tomatoes (about 1/2 pound)
• 3 scallions, thinly sliced
• 2 fresh or pickled jalapeno chiles, or to taste, seeded and minced (wear rubber gloves)
• 2 tablespoons fresh lime juice
• 2 tablespoons white wine vinegar
• 3 tablespoons olive oil
• 3 tablespoons chopped fresh coriander
• Salt and freshly ground black pepper
• Vegetable oil, for frying the tortillas
• 12 (7-inch) corn tortillas
• 3 cups roughly chopped watercress
• 1 1/2 cups thinly sliced red onion