Despite the inconvenience that this meal was to be grilled and we had our first snow storm today, it was a "keeper!"
1.25 pounds tip sirloin steak
1/4 cup balsamic vinegar
2 Tablespoons olive oil
1 1/2 teaspoons Dijon-style mustard
1 clove garlic, crushed
Combine all ingredients, except steak. Using 1/3 cup of the mixture, marinate the steak for 30 minutes. Place over medium heat grill for about 20 minutes, turning as needed. Use remaining marinade to baste asparagus (or vegetable of your choice).