Peel the bottom half of the asparagus spears with a peeler and cut them into 1cm diagonal slices. Place them in a microwave-safe container, cover loosely with plastic wrap, and microwave at 600W for 1 minute. Drain the water.

Cut the dinner rolls horizontally in half.

In a bowl, mix the mayonnaise, ketchup, sugar, and salt and pepper. Add the tuna and corn, and mix well.