Mom's Potato-Leek Soup

This is the simplest, purest version of potato leek soup. No butter, no cream, no roux. Just leeks and onions slowly extracted into chicken broth, then potatoes added to body it up, then everything blended into silk. The genius is in what gets left out.

Simmering the leeks and onions in broth for 25 minutes before the potatoes go in is the technique that builds deep flavor. The aromatics break down completely and infuse the entire pot before the potatoes start contributing starch. Skipping this step gives you a flat, plain potato puree.

Russet potatoes are the right choice because of their high starch content. They break down readily in the blender and create the velvety body that turns this soup from thin and brothy to creamy and rich without any actual cream.

Wash the leeks aggressively before slicing. They grow in sandy soil and pack grit between every layer. Slice first, then rinse in a bowl of cold water and lift out, leaving the dirt at the bottom. Skipping this step gives you gritty soup.

Blend in batches if your blender is small, and leave the lid slightly vented or covered with a folded towel. Hot soup creates steam that can blow the lid off and burn you. Better safe than soup-on-the-ceiling.

A generous turn of black pepper at the end is the only seasoning needed. The broth is already salted, the leeks are already sweet, the potatoes are already starchy.

Kitchen Tips

• Use only the white and pale green parts of the leeks. The dark green tops are tough and bitter.
• For an even smoother texture, push the blended soup through a fine sieve before serving.
• Save the leek tops for stock. They freeze well and add great flavor to homemade chicken stock.
• Garnish with a drizzle of good olive oil and a sprinkle of fresh chives for restaurant presentation.

Variations

• Add 1 cup of half-and-half or heavy cream at the end for a richer vichyssoise-style soup.
• Stir in a half pound of crumbled cooked bacon for a heartier version.
• Serve chilled in summer for a traditional French vichyssoise.