This soup is a generous soup; it can be as simple or elaborate as you like, and is almost impossible to screw up. Make it with salted water rather than chicken stock and it is vegan. Follow the recipe below, finishing with diced, smoked ham and shredded mature cheddar cheese and it is a stand-alone meal.
1 and 1/2 pounds fresh leeks, (trimmed of very dark green bit and mustachey looking end), washed and cut into thick rounds
Chicken or vegetable stock or salted water
Finishing options: Cream, diced, smoked ham, grated mature cheddar cheese, crunchy croutons
Drop the potatoes and leeks into a deep soup pot and cover with stock or salted water to come 3 inches about the veg. Simmer until soft, about 30 minutes. Puree with an immersion blender, or transfer to a food processor and process. Alternatively, go way old school and mash with a potato masher for a chunkier soup.
Hard to say how many this serves, a lot depends on the pot you use. In my pot it made enough for 8 servings.