1/2 cup fresh lime juice
1/4 cup Asian fish sauce*
1/4 cup granulated or light brown sugar
2 large garlic cloves, minced
2 teaspoons minced small fresh green chile such as Thai or serrano, including seeds, or 1 teaspoon dried hot red pepper flakes
16 very thin slices rare roast beef (3/4 to 1 lb)
16 large lettuce leaves, from 1 head Boston or 2 heads Bibb
16 fresh mint sprigs
16 fresh cilantro sprigs
2 carrots, cut into 1/8-inch-thick matchsticks


Whisk together lime juice, fish sauce, sugar, garlic, and chile in a medium bowl until sugar is dissolved. Toss roast beef with half of sauce to coat. Season with salt.
Arrange leaves, sprigs, and carrots on a platter and serve with beef. To assemble, fill each lettuce leaf with a slice of beef, a mint sprig, a cilantro sprig, and some carrots. Serve with remaining sauce.