Wash the konjac thoroughly and remove excess moisture.
Cut the whole wheat bread in half.
Slice the lettuce, cucumber, and tomato thinly and prepare them.
Pan-fry the konjac over low heat without oil for 2 minutes to remove any odor.
On the whole wheat bread, layer lettuce, cucumber, tomato, and grilled konjac in order.
Sprinkle a little salt, pepper, and mustard sauce as desired.
Cover with the other slice of bread to complete the sandwich.