Cucumber Soup With Seared Tuna Tartare

Name: Cucumber Soup With Seared Tuna Tartare
Ingredients: 1 large European cucumber—peeled, seeded and coarsely chopped, 1 tablespoon finely diced; 3/4 cup plain low-fat yogurt; 2 tablespoons water; 1/8 teaspoon mild curry powder; 1/8 teaspoon cayenne pepper; 2 tablespoons fresh lemon juice; Salt and freshly ground black pepper; 1 tablespoon extra-virgin olive oil; One 1/2-pound tuna steak; 3 tablespoons finely diced tomato; 1 small shallot, minced; 1 tablespoon snipped chives; 1 teaspoon finely chopped parsley