01 -
Turn on the oven and preheat to 400°F (200°C).
02 -
Cook the large shells following the instructions on their box until they're just tender. Strain then let them rest to cool off a bit.
03 -
Heat olive oil in a skillet, cooking the diced onion with half of the sliced sage leaves until the onions are soft. Stir together ricotta, pumpkin puree, nutmeg, salt, pepper, 1/3 cup shredded Gouda, minced garlic, and the sautéed onions in a bowl until blended.
04 -
Let the butter melt in a saucepan over medium heat until it browns just a little. Drop in the rest of the sage and stir for a minute until fragrant. Sprinkle the flour in and cook, stirring quickly, for about a minute. Pour in half of the cream and whisk until smooth and starting to thicken. Add the rest of the cream, some salt, and some pepper, stirring until the sauce reaches a creamy, thick consistency.
05 -
Spread a layer of the creamy sauce at the bottom of a baking pan. Stuff each cooked pasta shell with about two spoonfuls of the filling and line them up in the pan.
06 -
Cover the stuffed shells with the rest of the sauce, sprinkle over the last 1/3 cup of Gouda, and slide it into the oven. Bake for 20-25 minutes until the cheese bubbles.
07 -
Scatter fried sage leaves and a touch of ground black pepper on the shells before serving them up.