This cold salad is refreshing and pretty enough for a dinner party. The mustard in the vinaigrette compliments asparagus nicely.
Snap off the woody bottoms of asparagus spears and steam lightly till tender/crisp. Line spears up on a plate all facing the same way and tip so that any remaining moisture drains off.
Make a vinaigrette of olive oil and a splash of unflavored rice vinegar (available in Asian grocery stores). Beat in a large dollop of dijon mustard to make a creamy dressing, and adjust for salt.
Pour dressing over asparagus and marinate for an hour in the refrigerator, stirring occasionally. When ready to serve, garnish with cherry or grape tomatoes cut in half.