IN A SAUCEPAN, SAUTE THE CELERY and garlic in the butter until softened. Add the chicken stock, almonds and mace. Cover and simmer 30-to-40 minutes, stirring occasionally. Remove from the heat and let stand at room temperature for one hour. Puree in a blender or food processor. Return to the pot, stir in cream and heat 2-to-3 minutes. Do not let the soup come to a boil. Taste and add salt and pepper as needed. Serve sprinkled with toasted almonds.