2 teaspoons white wine vinegar 1/3 cup and 1 tablespoon and 1 teaspoon white wine 1 tablespoon and 1 teaspoon minced shallots 1 teaspoon wasabi paste, or to taste 1 teaspoon soy sauce | 1/3 cup unsalted butter, cubed salt and black pepper to taste 1 teaspoon olive oil, or as needed 1/3 cup chopped cilantro leaves 2 (6 ounce) fresh tuna steaks, 1 inch thick |