Easy Balsamic Glazed Steak Tips and Mushrooms

INGREDIENTS

1 1/2 lb

sirloin steak tips, flap meat, or flank steak, cut into 3-inch pieces

1/4 cup

tamari or soy sauce

2 tbsp

vegetable oil

2 tbsp

balsamic vinegar

1 tbsp

granulated sugar

2 cloves

garlic, minced

1 tsp

Dijon mustard

1/2 tsp

kosher salt

1/4 tsp

freshly ground black pepper

2 tbsp

vegetable oil

1 lb

cremini mushrooms, halved or quartered if large

2 tbsp

balsamic vinegar

2 tbsp

unsalted butter

Coarsely chopped fresh parsley leaves, for garnish (optional)