Remove thick, woody part of asparagus spears.
Bring water and salt to boil. Add asparagus and cook about 5 to 7 minutes or until crisp-tender and still bright green.
While asparagus is cooking, heat olive oil in a skillet and sauté onion and garlic. Add grapes, vinegar, mustard and pepper; heat thoroughly.
Spoon half of grape mixture onto serving platter, top with cooked asparagus and spoon remaining grape mixture over asparagus.Makes 4