- Preheat oven to 400°F (200°C).
- Place cabbage, carrots, celery, and onion in a baking dish. Lightly spray with cooking spray.
- Roast veggies in the oven for 1-1½ hours until soft but not mushy and lightly browned.
- Place bratwurst on top of veggies for the last 20 minutes to brown and warm through.
Dijon Mustard Vinaigrette:
- Combine Dijon mustard with apple cider vinegar.
- Add dried basil, Italian seasoning, garlic powder, and onion powder to taste.
- Mix until well combined.