Make the filling: Heat oil and butter in a wide saucepan and add the onion and garlic. Sprinkle a pinch salt over the onions and garlic. Cook over low heat for about 8 minutes until softened. Add about ½ cup water and simmer uncovered until the onions are caramelized. Stir in the pumpkin and cook for five minutes, to soften a little and to release its flavors. Add the tomato, wine, water, salt, and pepper. Cook until there is no longer any liquid in the pot and the pumpkin is chunky but very soft. Stir in the mint. Remove from heat and cool.

Bring all the ingredients for the sauce to a boil in a medium saucepan, reduce heat and simmer until thick, about 20 minutes.

In a separate bowl, combine the cheeses, eggs and nutmeg. Add salt and pepper to taste.

Preheat oven to 400° F/200° C.

Drizzle the bottom of a medium size nonstick baking pan with 2 cups of the sauce. The pan should be large enough to hold 4 raw lasagna sheets in one layer. Place the 4 lasagna sheets over the sauce. Spread 1 / 3 of the pumpkin filling on top and then 1 / 3 of cheese. Repeat two more times ending with a layer of cheese. Pour the remaining tomato sauce over the top layer and sprinkle with the grated cheese. Bake for 1 hour, or until set. Remove, cool for 20 – 30 minutes, and serve.