Spinach Salad and Roasted Garlic-Cider Vinaigrette

A good spinach salad always has a place in my meal plan.  And by good, I mean tricked-out with hard-boiled eggs, red onion, mushrooms, and, if I'm feeling decadent, some crispy bacon or prosciutto. To gild the lily, a little goat cheese or blue cheese perhaps.  A salad that great deserves a yummy dressing like this one.  It has lots of layered flavors from apple cider to roasted garlic to some more red onion.

Roasted Garlic-Cider Vinaigrette
Makes about 3 cups.

3 heads of roasted garlic (Wrap unpeeled garlic in foil and bake at 400° for 1 hour.  Remove from oven and let cool.)
3 tablespoons olive oil, divided
1 cup finely diced red onion diced finely
1 cup apple cider
3 tablespoons apple cider vinegar
Kosher salt and freshly ground pepper
Pinch of sugar if needed

In a large saute pan, heat the olive oil.  Add the onion and cook over medium-low heat until completely softened, 5-7 minutes.  Add the apple cider and simmer rapidly until reduced to about 1/2 cup.  Add the vinegar and squeeze the roasted garlic into the pan.  Add the remaining tablespoon of olive oil.  Stir until completely combined and season with salt and pepper.  Taste and add sugar if needed.

Serve the dressing warm so that it wilts the spinach slightly.