Why It Works
- Creamy Parmesan stock and roasted garlic provide savory depth to this simple soup.
- Simmering and blending potatoes with the stock gives the soup body without the need for a roux or extra dairy.
This creamy garlic soup relies heavily on the flavor of a stock made from leftover Parmesan rinds, which are simmered in water and then blended to produce a creamy liquid with a lot of Parmesan flavor. With that stock on hand, the soup comes together quickly and requires very few additional ingredients.
I added potatoes to give the soup texture and heft, without adding any distracting flavor. The result is a thick, creamy blend with a background cheesiness that lets the roasted garlic occupy center stage. While I think the soup is best when it’s strained after blending—t can be a little gritty if left unstrained—I’ve found that many people don’t notice the grittiness at all.
If you make the recipe as written, the flavor of the roasted garlic is present but not overwhelming. But if you’d like a more pronounced roasted garlic flavor, add more to your taste as you blend the soup.
- For the Soup:
- 3 tablespoons (45ml) extra-virgin olive oil
- 1 medium white onion (about 8 ounces; 225g), finely chopped
- Kosher salt and freshly ground black pepper
- 1 1/4 pounds (2 large potatoes; 570g) Yukon Gold potatoes, peeled and cut into 1-inch pieces
- 10 cloves roasted garlic, mashed to a paste
- 4 cups (1L) Parmesan stock, plus extra as needed
- Pinch of freshly grated nutmeg
- For Serving:
- Fresh basil leaves, small leaves left whole, large leaves torn into pieces
- Red pepper flakes
- Crusty bread
For the Soup: In a medium pot, heat olive oil over medium heat until shimmering. Add onion, season with salt and pepper, and cook, stirring frequently, until onion is softened, 6 to 8 minutes. Add potato and roasted garlic, season lightly with salt and pepper and continue to cook, stirring frequently, until onion just begins to brown, about 5 minutes.
Add Parmesan stock, and bring to boil over medium-high heat. Reduce heat to simmer and cook, stirring occasionally, until potatoes are tender and offer little to no resistance when poked with a paring knife, 12 to 15 minutes. Remove from heat.
Using an immersion or countertop blender, blend soup until completely smooth (if using a countertop blender, blend in batches, if necessary, and start blending at low speed before increasing to high). If soup is too thick, thin as needed with additional Parmesan stock. Season to taste with salt and pepper, and a pinch of nutmeg.
For Serving: Divide soup between warmed bowls, sprinkle with basil and red pepper flakes, and serve, passing bread at the table.
Make-Ahead and Storage
The finished soup can be refrigerated in an airtight container for up to 3 days.