Brats with Caramelized Onions and Cheddar Cheese Sauce

INGREDIENTS

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

pkg Johnsonville Original or Beer N' Bratwurst Brats

brat or hoagie buns