4 cups  Brussels Sprouts , halved

2 tbsp  Olive Oil

0.5  Red Onions , thinly sliced

3  Garlic Cloves , minced

1 tbsp  Sprigs Fresh Rosemary , minced

Salt , to taste

Pepper , to taste

0.33 cups  Hazelnuts , roasted, chopped

3 tbsp  Balsamic Vinegar

2 tsp  Maple Syrup