Cut the onions into half rings and fry with the chanterelles in half the vegetable oil, add the chili pepper. Cook until moisture is removed from the mushrooms.
Dissolve sugar in soy sauce, add the garlic passed through the press, the remaining oil and vinegar. Pour the mushroom marinade into the pan and simmer for 3 minutes.
Sprinkle the prepared mushrooms with any chopped herbs and serve.