Caramelize the Onions
In a large oven-safe skillet or Dutch oven, heat the olive oil and butter over medium heat. Add the sliced onions and cook for 20–25 minutes, stirring occasionally, until they’re soft and golden. Stir in the garlic and cook for another 1–2 minutes.
Add Brats and Liquid
Place the bratwursts on top of the onions. Pour in the beer and beef broth, then stir in the Dijon mustard. Season with salt and pepper.
Braise in the Oven
Bring everything to a gentle simmer, then transfer the skillet to the oven. Bake uncovered for 30–40 minutes, until the brats are fully cooked and infused with flavor.
Serve
Spoon the caramelized onions over the bratwursts and garnish with fresh parsley if desired.
Tips & Variations
No beer? You can use all beef broth instead.
For a little heat, add crushed red pepper or a splash of hot sauce.
Try different onions—red for a sharper taste or sweet onions for a milder flavor.
