This dairy-free potato leek soup can be served hot or cold.

Jessica Webster | AnnArbor.com

Lately the weather has got me feeling a little off-kilter. One day we’ve got a frost advisory, then days later we’re sweltering in 85 degrees and muggy humidity. Some days the temperature swing is 40 degrees from morning to night. It can be hard to know what season I’m cooking for.

What I really need is a dish that I can make ahead. Something that is just as good served cold as it is when it’s hot. Something like potato leek soup.

Potato leek soup — or some combination of broth, root vegetable and a member of the onion family — has been around for centuries. But at some point in (relatively) recent times, someone decided to add cream and serve it cold.

There are varying reports on how this came about, but everyone agrees that it was Louis Diat, a chef at the Ritz-Carlton in New York City in the early part of the twentieth century, who popularized the chilled version of potato leek soup and named if for Vichy, a town in the region of France where he was raised.

Whether you’re serving it hot and calling it potato leek soup, or chilling it and serving it as Vichyssoise, the basic preparation is the same. I’ve been working from the same recipe for years, but have started dreading the heaviness of all that cream.

So I set out to find a recipe with lots of flavor and a little bit less fat. I stumbled upon one from Bon Appetit from 1992 that called for just half a cup of cream and a variety of fresh herbs. This seemed promising, but I thought I would see if I could tinker with it to make it lighter.

I spread out my ingredients in the kitchen. Washed and chopped my leeks. Peeled and sliced up the potatoes. Prepped and chopped the herbs. Measured the broth. My intention was to divide the recipe into three separate pots. In one I would make the soup with cream. In the second I’d try it with half and half. And finally, my third pot would be made with whole milk. Whichever pot had the best flavor and texture would be my winner.

But something happened as I was in the pantry getting the chicken broth. I spotted a can of coconut milk. What if I made the soup with no dairy whatsoever? And what if I skipped the unspecified amount of Tabasco sauce in the Bon Appetit recipe and replaced it with some red curry paste?

I love the way this soup turned out. It’s still very rich, but I don’t feel like I need to take a nap after consuming a bowl. And bonus: if you use vegetable broth in place of chicken broth, you’ve got a delicious vegan soup!

Dairy-free potato leek soup adapted from Bon Appetit

• 3 pounds russet potatoes, peeled, cut into 1-inch pieces
• 5 cups canned low-salt chicken or vegetable broth
• 3 cups water
• 3 large leeks (white and pale green parts only), chopped
• 1 cup coconut milk
• 1/4 cup minced fresh chives or green onion tops
• 2 tablespoons minced fresh basil or 2 teaspoons dried, crumbled
• 2 teaspoons red curry paste

• Chopped fresh chives or green onion tops

Bring first 8 ingredients to boil in heavy large pot or Dutch oven over high heat. Reduce heat to medium-low and simmer until potatoes are very tender and soup thickens slightly, about 1 hour. Transfer half of the soup to blender and puree. Return puree to pot. Season with salt and pepper. Taste to test seasonings before serving.

Ladle hot soup into bowls, or chill for a few hours first. Garnish with chopped chives and serve.

Jessica Webster leads the Food & Grocery section for AnnArbor.com. You can reach her at JessicaWebster@AnnArbor.com.