In a small, heavy bottomed soup pot or casserole, melt 2 tablespoons of butter over medium heat. Add the onion and cook, stirring frequently, until softened and slightly translucent but not browned, about 4 minutes. Add the pumpkin, stock and half-and-half and stir to combine. Season generously with salt and pepper, reduce heat to medium low and cook 30 minutes, stirring occasionally. Remove from the heat, then transfer the mixture to the bowl of a food processor. **Puree for 10 seconds, until very smooth. Pour through a fine strainer into a clean pot. Add 6 tablespoons of butter and stir to combine.
In a small skillet, warm 4 tablespoons butter over medium heat until gently bubbling. Add the bread cubes, stir to coat with the butter and saute until golden brown. Transfer croutons using a slotted spoon to a small bowl lined with a paper towel.
Raise the heat under the soup to medium high and heat until very hot for several minutes but not boiling, stirring frequently with a whisk to blend the butter and to keep the soup from burning on the bottom. Ladle soup into bowls, sprinkle with diced Gruyere, croutons, chives and rosemary.
*Cooks note: Can replace fresh pumpkin with 1 (16-ounce) can of pumpkin puree and reduce the cooking time from 30 to 15 minutes.
** When blending hot liquids: Remove liquid from the heat and allow to cool for at least 5 minutes. Transfer liquid to a blender or food processor and fill it no more than halfway. If using a blender, release one corner of the lid. This prevents the vacuum effect that creates heat explosions. Place a towel over the top of the machine, pulse a few times then process on high speed until smooth.
Recipe courtesy of Carissa Seward