1In 2-quart saucepan, heat water, lentils and salt to boiling. Reduce heat; cover and simmer 12 to 15 minutes, stirring occasionally, until lentils are tender yet hold their shape; drain. Spoon into large bowl, cool 15 minutes.
2Into cooled lentils, lightly stir bread crumbs, seasoning, corn, and eggs. Form mixture into 6 patties about 1/2 inch thick and about 3 1/2 to 4 inches in diameter; place on platter or cookie sheet. Refrigerate 30 minutes (patties will firm up, making them easier to cook without falling apart.)
3In 12-inch nonstick skillet, heat 1 1/2 teaspoons oil over medium heat. Cook 3 patties 6 to 8 minutes, turning halfway through cooking, until golden brown. Transfer from skillet to heatproof platter; cover and keep warm. Repeat with remaining 1 1/2 teaspoons oil and patties.
4Place lettuce leaf on bottom half of each roll; top with cooked patty. Spread each with 1 1/2 teaspoons mayonnaise over patty; top with 1 slice tomato, 1 slice onion, and roll top.