1 large red onion, cut into ½ inch (1 cm) slices
1/2 cup (125 mL) olive oil
1 tablespoon (15 mL) kosher salt
1 teaspoon (5 mL) milled pepper
1 pound (500 g) white mushrooms, left whole
4 peppers (red/yellow/orange), seeded and cut into chunks
1 large bunch green asparagus, woody ends removed
1/2 cup (125 mL) red wine vinegar
1/4 cup (50 mL) bunch chopped fresh basil
Set onion slices on a plate, and brush both sides with olive oil. Season with salt and pepper. Set aside.
Place remaining vegetables in a bowl, toss with remaining oil and sprinkle in salt and pepper. Mix well, ensuring everything is coated.
Heat grill to medium. Place onion on one side of grill (it cooks better on its own); on the other, place remaining ingredients in a single layer, turning every 2-3 minutes, allowing the vegetables to caramelize. It may appear as though the vegetables are burning but a bit of charring adds to the flavour. It might be hard to get them off the grill but it is well worth it!
When vegetables are cooked, place in a large bowl; toss with red wine vinegar and fresh basil. Refrigerate 1/2 hour before serving to allow the flavours to blend. Makes 4-6 servings.