The small amount of mustard is a nice accent. An easy dish using mentsuyu noodle sauce.
I wanted to think of a way of preparing tomatoes and avocados for a Japanese meal.
Adjust the amount of mustard to taste. If you have time, chill the dish in the refrigerator for about 30 minutes after Step 3. The flavors will meld together and become even more delicious.
Enjoy Japanese food around the world.