Baked Italian Sausage and Potatoes

This is delicious simple and quick to throw together. Great with bread.

2 Tbsps balsamic vinegar
2 Tbsps olive oil
2 tsps fresh rosemary, chopped
1 garlic clove, minced
3 (a little under 1 lb) Italian sausages (sweet or hot), squeezed out of their casings and divided into quarters
3 (a little over 1lb) medium old potatoes, quartered (peel if you feel like it)
1 onion cut into 8ths (optional)
Salt and pepper, to taste
½ cup water

1. Preheat oven to 425°F.
2. Whisk together in a large bowl the vinegar, oil, rosemary and garlic.
3. Throw in the potato and sausage and stir until well covered in the marinade.
4. Place mixture into a ceramic or glass gratin dish lined with parchment paper (it sticks terribly to the dish without lining) and bake for 30 minutes, then turning and bake another 15, until sausage and potatoes are cooked through.