Start by bringing a large pot of salted water to a rolling boil over medium-high heat. Once boiling, gently add the potato gnocchi, cooking for about 2-3 minutes, or until they float to the surface, indicating they're ready. Use a slotted spoon to remove them from the pot and drain well, then set aside while you prepare the caramelized onions.

In a large skillet, heat 2 tablespoons of olive oil and 2 tablespoons of unsalted butter over medium heat until melted and bubbly. Add the thinly sliced onions and sauté them for approximately 15-20 minutes, stirring occasionally.

Once the onions are beautifully golden, sprinkle them with 1 teaspoon of sugar to deepen their caramelization. Continue sautéing for another 5-10 minutes, stirring as needed, until the onions turn a rich, golden brown.

Gently add the cooked gnocchi into the skillet with the caramelized onions. Stir carefully to combine, ensuring each gnocchi piece is coated with the luscious onion mixture. Allow everything to warm together for about 2 minutes.

Sprinkle approximately 1 cup of grated Gruyère cheese evenly over the gnocchi and onion mixture in the skillet. Remove the skillet from heat, then cover it with a lid for a minute or so.

Once the Gruyère has melted, uncover the skillet and give everything a good stir to fully combine. Season generously with salt and freshly ground black pepper to taste.

Once your Gnocchi with Caramelized Onions and Gruyère is piping hot and well-combined, transfer it to serving plates or a large dish. Optionally, garnish with fresh thyme leaves.