Brats with Caramelized Onions and Cheddar Cheese Sauce
Grilled brats tucked into buns with slow-cooked onions and tangy cheddar mustard sauce make a hearty, melty sandwich worth lingering over.
Prep 15 min · Cook 1 hr 5 min · Total 1 hr 20 min · Makes 5 sandwiches

Ingredients
- 3 medium yellow onions, sliced, 2 lbs
- 2 Tbsp butter
- 1 Tbsp olive oil
- Salt and freshly ground pepper
- 1 1/2 Tbsp butter
- 1 1/2 Tbsp flour
- 1/8 tsp garlic powder
- 3/4 cup milk, or more to thin if needed
- 5 oz. sharp cheddar cheese, shredded, 1 1/4 cups
- Salt and freshly ground black pepper
- 1 Tbsp spicy brown mustard
- 1 pkg. Johnsonville Original or Beer N' Bratwurst Brats
- 5 brat or hoagie buns
Directions
- For the onions, trim away the root and tip ends, halve the onions, and peel off the skins. Slice each half from tip end to root end. Set a heavy stainless steel or cast iron skillet over medium heat, melt the butter, then pour in the olive oil. Add the onions and stir them through the butter mixture until coated.
- Cook the onions for about 40 – 45 minutes, stirring now and then, about every 5 minutes. If they start to color too quickly, turn the heat down to medium-low as needed. When they are deep golden brown with that sweet caramelized flavor, add salt and pepper to taste.
- For the brats, heat a grill to medium-low. Cook the brats for 15 – 20 minutes, turning them often, until they are browned and the middle reaches 160 degrees.
- For the cheese sauce, make it while the brats are on the grill. Melt the butter in a small saucepan over medium heat. Stir in the flour and garlic powder, and cook, stirring the whole time, for 1 minute.
- Whisking as you go, slowly pour in the milk. Continue cooking and stirring until the sauce thickens and just starts to bubble lightly.
- Turn the heat to low, add the cheddar, and whisk until smooth and melted. Stir in the mustard, then season with salt to taste. If the sauce is too thick, loosen it with a little more milk. Warm it again over warm heat if needed.
- To build the sandwiches, set one brat in each bun, spoon the onions over the top, and finish with the cheddar cheese sauce. Serve warm.