1. Peel and deseed the pumpkin and cut into 1/2-inch cubes. Peel and chop the potato, onion, celery and garlic.
2. Place all ingredients in the bowl fitted with the ultrablade knife. Launch the P1 soup program at 210°F for 35 minutes.
3. Stir in cream, salt and pepper. Garnish with toasted nuts, croutons or fried onions