1.Combine oil, vinegar, thyme, garlic and onion in a large bowl. Drain onion and reserve vinegar mixture in the bowl.
2.Cook onion on a heated oiled barbecue flat plate until soft and browned lightly.
3.Meanwhile, in batches, cook asparagus and tomato on the barbecue flat plate until tender.
4.Add vegetables to bowl with reserved vinegar mixture and toss gently to combine.
You need four bunches of asparagus for this recipe.Note