Place the dried morel mushrooms in a bowl and cover with lukewarm water. Soak until softened, about 20 minutes.

Preheat the oven to 180°C / 350°F. Halve the spaghetti squash lengthwise and remove the seeds.

Rub the squash with olive oil, salt, and black pepper. Place the squash and garlic cloves in the baking dish.

Roast the squash and garlic for 60 minutes, until the squash is tender and its flesh separates into strands.

Drain the soaked morel mushrooms and rinse them well. Reserve the soaking liquid only if it is free from grit.

Melt 15 g / 0.5 oz of the butter in a skillet. Sauté the morel mushrooms over medium heat for 3 to 4 minutes.

Add the finely chopped shallot to the skillet. Cook until translucent, about 2 minutes.

Pour the dry white vermouth into the skillet. Simmer until it has reduced almost completely.

Turn off the heat and reserve the mushroom mixture. Bring a large pot of salted water to a boil.

Cook the lasagna sheets until flexible but still al dente. Reserve 200 ml / 6.8 fl oz of the pasta cooking water.

Cool the lasagna sheets under cold water. Lay them flat so they do not stick together.

Scrape the roasted spaghetti squash flesh into strands with a fork. Transfer the strands to a bowl.

Mash the roasted garlic cloves with a pinch of salt. Mix the garlic paste into the squash strands.

Grate 75 g / 2.6 oz of Pecorino cheese into the squash mixture. Stir in the walnut oil and adjust the seasoning.

Trim each cooked lasagna sheet into an even square. Divide the squash filling into four equal portions.

Place one portion of filling in the center of each lasagna square. Fold opposite edges over the filling to form four large ravioli.

Return the skillet of morels to medium heat. Add the reserved pasta cooking water and reduce the sauce by half.

Add the remaining 15 g / 0.5 oz butter to the reduced sauce. Stir vigorously until the sauce is glossy and emulsified.

Add the ravioli to the hot morel sauce. Baste them gently until heated through, about 2 to 3 minutes.

Transfer one ravioli to each serving plate. Spoon the morel sauce over them and finish with the remaining grated Pecorino cheese.