2 lbs waxy potatoes (like Yukon gold), peeled and sliced very thin, about 1/8 inch thick
6 cups baby spinach, chopped
1 1/2 cups heavy cream
1 cup Gruyere or Swiss cheese, grated
1 sprig rosemary
1 sprig thyme
1 garlic clove
Kosher salt and freshly ground pepper, to taste
Butter for greasing dish
Repeat, layering another third of the potatoes, more salt and pepper, and the rest of the spinach and cheese. Top with the last third of the potatoes and season with salt and pepper again.
Preheat oven to 375°F and liberally grease a 9×12-inch casserole dish with butter.
In a large pan, cook spinach over medium heat, stirring frequently, until it becomes wilted and cooks down, 2-3 minutes. Set aside.
Bring cream, garlic, rosemary, and thyme to a boil in a medium saucepan over medium heat, removing it from the heat as soon as it reaches a boil.
Now that spinach has cooled, place spinach in a paper towel or kitchen towel and squeeze out excess liquid.
Arrange 1/3 of the potatoes in the prepared casserole dish, overlapping slightly. Season liberally with salt and pepper and top with half of the spinach and 1/2 cup of cheese.
Strain the cream from the saucepan to remove herb sprigs and garlic and pour liquid over potatoes.
Cover dish with foil and bake until potatoes are tender when pierced with a knife, about 45 minutes. Remove foil and continue to bake until golden and bubbly, about 15-20 more minutes.
Let rest 10 minutes before serving. Enjoy!
Source : allrecipes.com