Autumn has finally descended upon Sydney. There is a definite chill in the air. Cooler weather is synonymous with comfort food. In my books there is nothing more comforting on a chilly day than a big bowl of warming soup.

A couple of months ago I posted a recipe for a deliciously creamy Non Dairy Potato and Leek Soup. This is exactly what I felt like eating today. However, it being a fast day I would need to be careful with the tedious  calorie count.

Since embarking on the 5-2 Challenge I have become a slave to calorie counting and  ingredient substitution. Quite recently I successfully substituted Cauliflower and Cannellini Bean Mash for regular mashed potatoes. All the texture and creaminess of a comforting mash for a fraction of the calories. With a small head of cauliflower in the refrigerator I set about reinventing a potato and leek soup recipe to accommodate my fast day. I used just enough potato to give the soup structure. The result was awesome. Deliciously creamy with just a hint of cauliflower. Just 74 calories for a standard 250 ml cup leaving more than enough room for a crispy garnish for my soup.

I contemplated oven baked croutons but on a whim googled the calorie count of  crisp crumbled shards of prosciutto. Surprisingly, according to the Fatsecret website 100 grams of prosciutto contains just 200 calories. Sliced to order by my very obliging deli 100 g yielded 10 paper-thin slices of prosciutto. Crisped over a dry griddle pan they provided the perfect finishing touch to a very creamy soup. The total calorie count for this meal was so impressive I managed to squeeze in two small slices of a seeded bread stick.

All in all a very satisfying fast day coming in just under my daily 500 calorie limit.

Cauliflower, Potato and Leek Soup With Crispy Prosciutto

Makes 10 cups  (74 calories per cup of soup plus 20 calories per each thin slice prosciutto)

1 tablespoon olive oil (120 calories)
1 brown onion, diced (46 calories)
3 cloves garlic, crushed (12 calories)
4 celery sticks, sliced (34 calories)
2 leeks, white part only, sliced ( 54 calories)
3 medium potatoes (1 1/2 cups) peeled and diced (160 calories)
1 medium head cauliflower, divided into small florets (144 calories)
2 litres  (8 cups) chicken or vegetable stock (160 calories)
sea salt and freshly ground pepper, to season

2 tablespoon  chives, snipped (2 calories) to garnish
10 slices (100g) prosciutto, very thinly sliced (200 calories) to garnish

HEAT oil in a large cast iron or similar saucepan over medium-high heat. Add onion and garlic and cook, stirring, for 5 minutes or until soft and transparent.
ADD the leeks and cook, stirring, for a further 5 minutes until leeks soften. Do not allow the leeks or onions to brown.
ADD the cauliflower, celery and potato and cook, stirring for a further 5 minutes, until the potato begins to soften a little.
ADD the stock and bring to the boil. Reduce heat to medium and gently boil, uncovered, for 20 minutes or until potato is cooked. Remove from heat and set aside for 10 minutes to cool.
PUREE soup in batches in the jug of a blender or in the pot with a hand-held immersion stick blender.
HEAT a griddle pan over a high flame. When hot quickly sear prosciutto slices on both sides until crisp.
REHEAT soup just before serving.  Check seasoning. Ladle the soup among serving bowls.  Serve immediately garnished with snipped chives and crumbled prosciutto.