Heat the olive oil in a small or medium skillet on medium heat. Add the onion and cook for 2-3 minutes.
Lower the heat slightly and add the asparagus to the skillet. Cover and cook, stirring occasionally until the asparagus is slightly softened, about 7 minutes. If the vegetables are sticking to the skillet, add a small amount of water as needed.
Remove the vegetables from the heat and transfer to a small mixing bowl. Add all of the remaining ingredients and mix well to combine. Adjust seasonings to your taste and serve warm or cooled.