Ingredients:
2 Tbsp olive oil
1 lb onions, about 3, to yield 3 cups chopped
2 tsp salt, plus more to adjust
3 garlic cloves, minced, to yield about 1 tablespoon
¾ lb unpeeled carrots, about 4 medium, to yield 2 cups chopped
4 medium celery ribs, to yield about 2 cups chopped
1½ lb leeks, about 5 medium, to yield 3 cups white and light green parts halved lengthwise and sliced
3 lb thin-skinned potatoes, about 10, to yield 10 cups chopped
6 cups water
2 cups whole milk
4 Tbsp butter
Equipment:
Chef’s knife
Cutting board
8-quart pot with lid
Bowls
Measuring cups and spoons
Wooden spatula or spoon
Blender or an immersion blender
Ladle
Pot holders, dish cloth
Directions:
Prepare all veggies by washing, chopping, slicing, or mincing them as noted in the ingredients list.
1. Warm an 8-quart pot over medium-high heat for 1 minute. Add the olive oil, onion and salt. Cover, reduce the heat to medium-low, and cook, stirring occasionally, until the onions are softened, about 15 minutes. Add the garlic, stir together, cover and cook for a minute more.
2. Stir in the carrots and celery, cover and cook for 10 minutes. Next, add the leeks and potatoes. Stir, cover, and cook together for another 10 minutes.
3. Carefully add the water to the pot. Bring it to a boil, then uncover and reduce the heat to a simmer and cook until the vegetables are tender, about 20 minutes. Remove from the heat
4. For a creamy texture, carefully submerge the blade of an immersion blender into the soup, turn it on and move it around the pot to puree the soup. Or, ladle small batches into a blender or food processor and blend just until smooth. Avoid over-processing, as the potatoes will become gummy.
CAUTION: Never fill a blender more than one-quarter full with hot liquid. The steam from hot soup can spray out, causing serious injury. Using small batches of cooled vegetables and stock helps prevent this risk.
5. Warm the soup over medium heat, stirring frequently to prevent sticking and burning. Stir in the milk, butter and black pepper. Simmer for a few minutes to blend the flavors. Turn off the heat and stir in the chives, parsley and tarragon. Taste and adjust.
Dig Deeper:
Don’t rush cooking the onions, as this forms the flavor base. Always cook onions thoroughly before adding acids like tomatoes, vinegar, lemon or wine because acids stop their softening and flavor development.
As you add ingredients to a pan, season gently with salt, keeping in mind “salt as you go.” Salt draws out moisture, which forms a medium for vegetables to cook in. As the moisture evaporates, flavors concentrate. Salt also softens pectin, allowing vegetables to cook more quickly, become tender faster, and retain their color.
Leeks thrive in sandy soil. To clean them, slice off the dark green tops that can be saved for stock, and trim the root ends. Cut the white and light green centers in half lengthwise. In a bowl of cold water, separate and agitate the layers to remove dirt. If any grit is detected while slicing, put the slices into a bowl of clean, cold water, agitate, and rinse thoroughly.
Reduce the heat after adding delicate herbs like chives, parsley or tarragon, as excessive heat diminishes their flavor. It’s best to add them just before serving.