Pumpkin is one of the winter squashes and tastes fine if it is a sugar pumpkin. However, most pumpkins that are grown for Halloween jack o lanterns have very little flavor. Other winter squashes have great flavor such as kabochi, red curry, or butternut squash. For this recipe use any winter squash that appeals to you, the heavier the better.
To prepare the squash, cut it in half and lay it cut side down on a lightly oiled baking sheet. Bake in a 400 degree oven until the squash is soft when pierced with a fork, about 1 hour. Remove from the oven and let cool.
To make the croutons, cut the crusts from the bread, and cut the bread into 1/4 inch dice. Heat enough oil and butter in a 8 or 9 inch frying pan until hot. Toss in all the bread at once and continue cooking and stirring until the croutons are lightly browned. Transfer to a plate and sprinkle with salt.
To make the soup, cook the onion in a little oil with half a teaspoon of salt in a saucepan over medium high heat and cook, stirring, until the onion is soft. Remove seeds and skin from the cooked squash. Add the cooked squash with the water or stock, and continue simmering for another 10 minutes.
Puree with an immersion blender. Add salt and pepper to taste.
To serve, cut the prosciutto into 1/4 inch dice. Place a large quenelle shape of fromage blanc in the bottom of 8 bowls. Surround with croutons and prosciutto. Pour around enough soup so that the cream barely shows. Serve warm.