Although I spent a lot longer cooking up the turkey and all the sides for this year's Christmas dinner, it was this simple soup that I served as a starter that won the most praise.

And it is very good. A simple but very rich and creamy sweet potato soup with a hint of balancing Dijon mustard – and made from just a few ingredients in 20 minutes or so.

Because of the simplicity of the recipe, it's the quality of the few ingredients that makes or breaks the soup. Although you can use canned or powdered chicken stock here, the soup will be much much better if made with a homemade chicken or turkey stock.

Creamy Mustard Spiced Sweet Potato Soup

As with most vegetable cream soups – precision in quantities of ingredients used is not critical. Use approximate amounts and cook with your eyes, nose and mouth wide open – tasting and modifying quantities as necessary (Not rocket science stuff…if it's too thick; add a little more broth etc.)

• 2 pounds of sweet potatoes (yams) I use the paler skinned and fleshed variety, but the deeply orange ones will also work.
• 1 white onion, chopped
• 6 cups of homemade chicken stock (turkey stock can be used here as well)
• ¾ cup of heavy cream
• 1 Tbls of sharp Dijon mustard
• Salt and pepper A little olive oil (or butter) for sautéing

1. Heat a heavy soup pot over medium. When hot, add in a couple of Tbls of olive oil and sauté until softened. You don’t want the onion to brown, so stir occasionally and watch the heat.
2. Peel and cube the sweet potatoes into 1 inch chunks. When the onions have softened (about 5 minutes) add in the sweet potatoes and all of the chicken stock.
3. Bring the soup up to a simmer and turn the heat down to medium low (or whatever heat level maintains a gentle simmer) and let the soup cook until the sweet potatoes are nice and soft.
4. Once the potatoes have softened (about 20 minutes) transfer everything from the soup pot to a blender or food processor (in batches probably) and process it until smooth.
5. Return the soup to your cooking pot (or serving bowl) and stir in the cream and mustard. Add a few good cranks of the pepper grinder and a few generous pinches of salt to taste.
6. Taste the soup for balance. Without the mustard the soup would have a cloying sweetness. The point of the mustard is not to make the soup taste mustardy (Indeed people shouldn’t really be able to taste the mustard) but rather to balance the sweetness. Add in mustard little by little until the soup has reached the point between sweetness and mustardyness'.
7. Serve garnished with a dollop of yogurt in the center of each bowl and a sprinkle of finely chopped green onions over the top.

Delicious!