Peel the onion and chop it finely. Peel the apple and cut it into strips.
In a frying pan, fry the onion and apples in 1 tablespoon of oil over medium heat. Add the cider vinegar. Cook for another 5 minutes. Season with salt and pepper.
Preheat your oven to 160°C on grill mode.
Cut the buns in thickness. Prick the sausages with a fork.
Put the sausages on the grill for 15 minutes and the bread for 3 minutes.
Mix the mustard and honey.
Top the buns with apples on the sides and the frankfurter in the middle.
Finish with some red onion pickles and a dash of honey mustard