Preheat the oven to 200C/400F
Arrange the mushrooms on skewers, with a slice of onion in between each one.
Coat the skewers in BBQ sauce (a bit messy, but easiest to use your hands!)
Arrange on a baking sheet. Season with salt and pepper.
Pop into the oven for 20-30 minutes.
Garnish with freshly chopped parsley!