Prepare balsamic vinegar reduction by adding 1 cup of balsamic vinegar to a small pot. Heat on high until the mixture boils, then turn down to simmer for 20 minutes. The reduction should yield 1/2 cup of vinegar. Store in an airtight container.
Prepare asparagus by cutting off about 1 inch of the bottom end of the asparagus, lay asparagus on a sheet pan drizzle with oil and sprinkle with salt. Roast on medium heat on a grill for about 10 minutes turning the asparagus over.
Cooking time with vary with the thickness of the asparagus. Remove asparagus from grill when done. If desired squeeze 1/2 of a lemon over the asparagus. I do not think the Olive Garden does this, but I think it really helps to bring out the flavor of the asparagus. Prepare Parmesan sauce by adding heavy cream and 2 tablespoons of grated Parmesan cheese in a small pot or skillet.
Simmer on low for about 10 - 12 minutes. The cream should reduce by 20% in volume. To prepare plate some of the cooked asparaguses on a plate, drizzle balsamic vinegar on top. Garnish with 1 tablespoon Parmesan cheese, and then serve with the sauce. Garnish with fresh chopped tomatoes if desired.
Recipe Tips
If you can only find large asparagus, you can peel the stalk with a vegetable peeler, this will peel away the tough part of the asparagus!