No need to waste precious minutes peeling potatoes! Scrub and pierce the sweet potatoes and russet potatoes and place them on the barbecue early in the day. Roast potatoes on MEDIUM for 45–50 minutes. Let cool for 15 minutes, then simply scoop out the flesh, for use in the soup later.
When you have 15 minutes of free time, complete the soup! In a stock pot, melt butter and add the onion, leek, garlic, carrots and bay leaf. Cook over low heat, stirring until the vegetables have softened.
Add the chicken broth, wine and water and simmer, covered, for 15 minutes. Add the flesh of the sweet potatoes and russet potatoes and simmer 10 minutes, discard the bay leaf. In a blender, puree the soup in batches, until it is very smooth. Season the soup with salt and pepper. This soup may be made a day or 2 in advance. Thin with additional stock, or water, as required.
To make crispy sage garnish: Heat 3 tbsp of oil in a frying pan. When oil begins to sizzle, gently drop in clean and dry sage leaves and allow to fry for 1–2 minutes. Remove carefully and let cool on a paper towel. Sprinkle with coarse sea salt.
Serve soup in individual wide mouthed bowls, topping each with a crispy sage leaf and a tablespoon of Stilton cheese.

MAKE IT EASIER WITH THESE GRILL ACCESSORIES.