Preheat a pan for 2 min on medium. Add a drizzle of olive oil, the onion and shallots.
Let them caramelize at medium heat for 40 min, mixing often. Add water in 2 tbsp increments to deglaze.
Add in your salt, nutmeg, thyme and balsamic. Let them go another 20-30 min or until deeply golden.
Push the onions to the side, add in butter and melt. Add in flour, mix it together for 3 min. Add in the broth and let it thicken starting with 2 cups, adding the rest as needed.
Cut the potatoes in a hasselback pattern.
Mix the olive oil with a pinch of salt, onion powder, white pepper and garlic powder.
Brush the oil on the potatoes.
Add the onions to a baking dish, sprinkle half the cheese. Arrange the potatoes and sprinkle the rest of the cheese.
Bake covered at 400F for 40 min, then uncovered for another 20-30 min at 425F.
Add more parm, chives and black pepper, and that's it.
Hosting tip: the onions & broth mixture can be made up to 2 days ahead; arrange the potatoes and cheese and keep covered/refrigerated up to 12 hrs, then bake before serving. From Nadia Aidi on Instagram.
