Cut the pumpkin into 1 cm (approximately 1/2 inch) thick slices.
Rinse and slice the scallions. Sauté in the butter, then sprinkle with the flour and stir until coated. Deglaze with the white wine, then add the milk and bring to a boil stirring constantly. Stir in the creme fraiche, and simmer. Season to taste with salt and nutmeg. Place a layer of the sauce in a baking dish, then top with a layer of the pumpkin. Repeat the layers until all the ingredients have been used, finishing with a layer of sauce. Sprinkle with the parmesan and breadcumbs. Bake in a 180°C (approximately 350°F) oven for 25-30 minutes, until golden brown.
Peel the potatoes and cut into wedges. Season with salt, and sauté in 2 tablespoons of oil. Cook for 25 minutes, until golden brown, stirring occasionally.
Toast the almonds in a dry pan until golden brown.
Rinse and trim the broccoli. Blanch in boiling salted water for 5 minutes until al dente. Remove from the water, and sauté in a pan with the remaining oil. Season to taste with salt, then mix in the almonds.
Transfer the gratin to warmed plates, and serve with the potatoes and broccoli.