Seared Tuna with Coconut Sauce

Name: Seared Tuna with Coconut Sauce
Ingredients: Coconut Curry Sauce:; 1 cup homemade fish stock or bottled clam juice; 1 cup canned coconut milk; 1/2 cup canned cream of coconut; 2 garlic cloves, crushed; 2 tablespoons chopped fresh ginger; 1/2 cup minced scallions; 2 tablespoons chopped lemon grass (optional); 2 tablespoons curry powder; 2 tablespoons light soy sauce; 1/2 teaspoon dried red pepper flakes; 4 (8-ounce) tuna steaks; 1/2 teaspoon salt; 1 teaspoon coarsely ground black pepper; 2 tablespoons olive oil