Tonnato is a type of Italian sauce made from tuna, capers, anchovies, lemon juice, egg yolks, and olive oil, all blended together. Typically served cold, tonnato can be used to add umami to just about any dish. Some foods possess a natural taste of umami, such as meats, seafood, cheese, mushrooms, tomatoes, and fermented foods (per WebMD). Monosodium glutamate (MSG) –– a substance that is sometimes mistaken for umami but that does not occur naturally in foods –– is believed to further enhance the flavor of umami.
But back to tonnato. Umami-rich tonnato is wonderfully creamy, but also tart and tangy. You can use it as a spread on sandwiches, drizzle over roasted vegetables or salads, or dip your favorite raw vegetables into it. Or, try your hand at making a popular appetizer called Vitello tonnato from northwestern Italy (the Piedmont region). This delicate dish involves tender, boiled, and sliced veal topped with tonnato sauce.
And not only does tuna make a great ingredient in a sauce, but tuna is also excellent when covered with sauce. Saucy condiments that go well with tuna include mayonnaise, harissa, and dijon mustard. You can also reach for Greek yogurt, cottage cheese, or crème fraîche to jazz up your canned tuna.