Preheat your oven to 390ºF (200ºC) and grease a 13-inch round baking dish with butter or olive oil.

Bring salted water to a boil and cook the store-bought potato gnocchi according to package instructions, usually around 2-3 minutes until they float.

Peel the pumpkin and slice it thinly, no thicker than 0.2 inches, and ensure each slice is about twice the length of the gnocchi.

Slice the red onion into half-moon shapes and set aside.

In a large mixing bowl, combine the cooked gnocchi, sliced pumpkin, onion, olive oil, and fresh thyme leaves. Gently toss to combine.

In another mixing bowl, whisk together the heavy cream, egg yolks, and half of the shredded mozzarella until smooth, then pour over the gnocchi mixture.

Transfer the mixture into the greased baking dish and sprinkle remaining mozzarella and grated Parmesan over the top. Bake for 40 minutes, or until bubbly and golden brown.