No matter how many dazzling things we have the good fortune to eat in our lives, we often remember the simplest meals with as much power and affection as the fanciest. A humble, pureed vegetable soup is among those particular pleasures. Also, Proustian prose aside, if you're feeling lazy, you can get from a few ingredients to deliciousness in no time.
The only work involved here is remembering to stir the leeks fairly often for 20 minutes. You'll want to keep them on medium-low heat and take the full amount of cooking time so they become meltingly tender and only lightly browned; turning up the heat to rush the process may result in them burning, and they won't get as lushly soft over higher heat.
You could absolutely add some fresh herbs here, from basil to thyme to plain old parsley if you want a different twist, but taste the soup as-is first. You may very well want to stick with the simple version where the flavor of the leeks shines through unobstructed (it's a bit richer than you might think). If you do want to add fresh herbs, they can be added at the end when you puree the soup, or just strew a few leaves, chopped or whole, on top of each serving.
Use vegetable broth and the soup is vegetarian. Skip the cream (and use an extra tablespoon of oil instead of the butter) and it is dairy-free and vegan. It can be made ahead and kept in the refrigerator for a couple of days. Either reheat over low heat, or serve chilled. It will thicken in the fridge, so may need an extra glug or two of broth or water.
Silky Leek Soup
Start to finish: 40 minutes
1 tablespoon unsalted butter
1 tablespoon olive oil, plus extra for drizzling
6 large leeks, white and light green parts only, thinly sliced and well rinsed
1 garlic clove, minced
Kosher salt and freshly ground black pepper to taste
1 (14.5 ounce) can less-sodium chicken or vegetable broth
3 tablespoons heavy cream
Chopped fresh herbs to serve (optional)
In a large pot, heat the butter and 1 tablespoon olive oil over medium-low heat until the butter is melted. Add the leeks and garlic, season with salt and pepper, and sauté, stirring frequently, for about 20 minutes until they are very lightly browned and quite tender. Remove a few tablespoons of the leek mixture and set aside. Add the broth and 2 cups of water and bring to a simmer over medium heat. Cook until the leeks are very soft, about 10 minutes.
Puree the leeks and liquid in a blender or food processor until completely smooth, and return to the pot. Do this in two batches, transferring the first half to a bowl if necessary (too much hot liquid in a blender or food processor is not a good idea). Stir in the heavy cream, and taste and adjust seasoning as needed. Serve immediately, or refrigerate and serve chilled. Place a small mound of the reserved sautéed leeks on top of each serving, and give each bowl a drizzle of olive oil and a sprinkle of any minced herbs you like. Season once more with salt and pepper.
Nutrition information per serving: 184 calories; 86 calories from fat; 11 g fat ( 5 g saturated; 0 g trans fats); 23 mg cholesterol; 541 mg sodium; 20 g carbohydrate; 2 g fiber; 6 g sugar; 3 g protein.