Prosciutto -- air-dried Italian ham -- has a sweet, salty taste and a pleasant aroma. Its texture is dense and silky, the result of being pressed during curing. Here, it makes a flavorful alternative to bacon in our version of a BLT.
Using a garlic press, press the garlic clove into a small bowl. Whisk in the mayonnaise and lemon juice. Spread one side of each slice of toasted bread with garlic mayonnaise. Divide Crispy Prosciutto over 4 slices; top each with 1 leaf romaine lettuce and thinly sliced plum tomatoes. Top with remaining bread slices, mayonnaise side down. Trim crusts as desired, and serve immediately.