Step 1

Preheat the grill to high.

Step 2

Prepare the red onions: Cut onions in half from root to tip, then cut the halves into ½-inch slices. Pull the slices apart and place them into a disposable grill pan. Toss with 2 tablespoons olive oil, ½ teaspoon kosher salt and ¼ teaspoon pepper.

Step 3

Prepare the asparagus: Place the spears in a baking dish and toss with 2 tablespoons olive oil, ¼ teaspoon kosher salt and ¼ teaspoon pepper.

Step 4

Place the pan of onions on the grill, along with the asparagus spears (be sure to place spears perpendicular to grates so they don't fall through). Set the asparagus dish next to the grill (do not clean). Cover and cook the vegetables for 2-3 minutes. Open the cover and, using tongs, turn the asparagus. Cover and cook 1 -2 minutes more, until the asparagus spears are nicely browned and tender-crisp. Remove the asparagus from the grill and place back in the baking dish. Stir the onions, cover, and continue cooking for about 15 - 25 minutes, stirring every few minutes, until tender and caramelized. In the meantime, transfer the asparagus spears to a cutting board and cut into 1½-inch pieces. Place back in the baking dish and toss with finished grilled onions. Add the sugar and balsamic vinegar and toss well. Taste and adjust the seasoning if necessary (I usually add a good ¼ teaspoon more salt). Transfer to serving platter and serve hot or room temperature.

Step 5

Note: Make your own disposable grill pan. Shape two layers of heavy duty aluminum foil over a 9 x 13-inch baking dish. Remove foil from pan.