Potato Pear and Onion Gratin

Ingredients:
12 tablespoons butter divided
2 pounds white onions sliced
2 tablespoons chopped fresh thyme
4 teaspoons fine sea salt divided
2/3 cup water
2/3 cup dry white wine
4 teaspoons granulated sugar
2-1/2 pounds Yukon gold potatoes peeled and cut into 1/4" thick rounds
2 pounds pears peeled halved cored and cut into 1/4" thick slices

Directions:
Preheat oven to 400 then butter
a rectangular glass baking dish.
Melt 6 tablespoons butter in large
nonstick skillet over medium heat.
Add onions, thyme and 2 teaspoons salt then
sauté until onions are translucent about 10 minutes.
Increase heat to medium high then sauté
until onions are tender about 8 minutes longer.
Remove from heat then add remaining
6 tablespoons butter, 2/3 cup water, wine and sugar.
Stir and swirl skillet to combine then bring to a boil.
Cool onion mixture to lukewarm.
Combine potatoes, pears, remaining
2 teaspoons salt and onion mixture in large bowl.
Toss gently to blend then transfer
to prepared baking dish spreading evenly.
Cover dish with parchment paper then cover with foil shiny side down.
Bake gratin until potatoes are tender about 55 minutes.
Uncover and bake until top browns and
juices bubble thickly about 20 minutes longer.
Let gratin stand 15 minutes before serving.