Ingredients:

6 Tablespoons unsalted butter
3 medium leeks, halved and thinly sliced
2 medium onions, finely chopped
3 large garlic cloves, thinly sliced
Kosher salt, to taste
Ground black pepper, to taste
12 large celery ribs (2 pounds), trimmed and thinly sliced
4 ounces bacon, finely diced
Three 1/2-inch-thick slices of country bread, cut into 1/2-inch dice
1/2 cup  sour cream
1/2 cup chilled heavy cream (optional)
Lemon olive oil, for drizzling

Directions:
In a large saucepan, melt 4 tablespoons of the butter. Add the leeks, onions, garlic and a generous pinch each of salt and pepper and cook over moderately high heat, stirring, until softened but not browned, about 12 minutes. Add the celery and cook, stirring, until just starting to soften, about 3 minutes. Add 8 cups of water and bring to a boil, then reduce the heat to moderate. Simmer, stirring occasionally, until the vegetables are very tender, 35 to 40 minutes.

Meanwhile, in a large skillet, cook the bacon over moderate heat, stirring occasionally, until browned and crisp, 8 minutes. Using a slotted spoon, transfer the bacon to half of a paper towel–lined baking sheet to drain. Melt the remaining 2 tablespoons of butter in the bacon fat. Add the bread and cook over moderately high heat, stirring, until browned and crisp, 8 minutes. Transfer to the other side of the prepared baking sheet; season with salt and pepper.

Working in batches, puree the soup in a blender until smooth. Return the soup to the saucepan, whisk in the sour cream and season with salt and pepper.

Beat cream in a bowl with an electric mixer at medium speed until it almost forms soft peaks.

Serve the soup hot, topped with the bacon, croutons. whipped cream and a drizzle of lemon olive oil.

Cook’s Notes:
The soup can be refrigerated for 3 days. Rewarm before serving. Do not whip cream ahead.