Cured anchovies, packed with umami, deepen the flavor of sauces and salad dressings. They're available packed in salt or filleted and packed in oil, and how much prep they need depends on which type you use.
Oil-packed anchovies are usually used straight from the tin or jar without rinsing, but should be blotted with paper towels before use, mbfant says on Chowhound. The oil they're packed in often isn't of high quality, but you can pour it off and replace it with extra-virgin olive oil for keeping, mbfant says. Even oil-packed anchovies are very salty, so taste before adding any other salt to a dish that includes them.
Salt-packed anchovies should either be soaked for several minutes or thoroughly rinsed in cool water in order to remove the excess salt, and they often need to be filleted—a tedious process that gets easier with practice, mbfant says. Though oil-packed anchovies are more common, salt-packed are generally better if you're willing to deal with the prep, she says.