We call this ‘Parisian Perfection.’ The savory, rich taste has everyone coming back for more, and I’ve made it at least five times this month!

Preheat your oven to 375°F (190°C).

In a large skillet, melt the butter with the olive oil over medium heat. Add the onions and cook, stirring occasionally, until they are caramelized and golden brown, about 20 minutes.

While the onions are cooking, thinly slice the potatoes and set them aside.

Once the onions are caramelized, add the beef broth to the skillet and bring it to a simmer. Cook for an additional 5 minutes, then remove from heat.

In a greased 9×13 inch baking dish, layer half of the sliced potatoes. Sprinkle with half of the salt, pepper, and thyme.

Pour half of the onion and broth mixture over the potatoes, then sprinkle with half of the Gruyère cheese.

Repeat the layers with the remaining potatoes, seasonings, onion mixture, and cheese.

Pour the heavy cream evenly over the top of the dish.

Cover the baking dish with foil and bake in the preheated oven for 45 minutes.

Remove the foil and bake for an additional 15 minutes, or until the potatoes are tender and the top is golden brown and bubbly.