Pretzel hot dog with onion Jam and cauliflower & oat crumble

Ingredients

• ½ jar of Hengstenberg hot dog gherkins
• 4 long pretzel rolls
• 4 chunky "bratwurst" sausages
• 1 red onion
• 30 ml Hengstenberg Aceto Balsamico di Modena IGP
• 4 tbsp mustard
• 4 tbsp mayonnaise
• 8 salad leaves (e.g. Lollo Bianco, Romaine)
• ¼ cauliflower
• 150 g jumbo oat flakes
• 10 g brown sugar
• 20 g butter
• A pinch of sea salt
• 1 tbsp olive oil