Optional But Recommended Step: While the oven is preheating, pierce brats with a fork several times. Place them in a large stock pan and cover with beer (or cider or stock.) Bring to a boil and then simmer for 10 minutes. Remove brats from pan and pat dry. Discard the cooking liquid.
In a small bowl, whisk maple syrup, mustard, oil, garlic, salt, and pepper together.
Place potatoes, cabbage, onions, and par-boiled brats onto a large-rimmed sheet pan. Drizzle with the mustard dressing and using your hands, toss to coat. Spread out in an even layer.
Roast for 35-40 minutes, or until cabbage is browned and potatoes are cooked through.
Notes
Gluten-Free Modification: Be sure your brats are gluten-free and do not use beer to boil your bratwurst. Either skip that step OR use apple cider or stock.Beer/Alternatives to Beer: If you opt to par-boil your brats before roasting, I recommend selecting a German lager, such as Sam Adams Oktoberfest for the most flavor. If you are opposed to using beer, you can par-boil in apple cider or chicken stock which also imparts delicious flavor. Bratwurst: You can use any type of Bratwurst you like--Turkey, Chicken, Beef, or Pork.Potatoes: If you don't have new potatoes, use red potatoes or even russet potatoes, cut into fourths.Storage: Leftovers can be stored in the refrigerator for up to 3 days. It is best to reheat in a 400-degree F oven for 15 minutes to keep everything nice and crispy when serving leftovers.