- 4 tablespoons unsalted butter
- 2 cups finely chopped yellow onion
- 5 cups low-sodium chicken or vegetable broth
- 8 cups frozen green peas (from four 10-ounce packages), thawed slightly
- 1 1/2 cups loosely packed fresh mint leaves
- 2 teaspoons kosher salt
- 2 teaspoons granulated sugar
- Melt the butter in a large saucepan over medium heat. Add the onion and cook until softened, 3 to 4 minutes.
- Add the broth, peas, mint, salt, and sugar. Remove from heat.
- Transfer half the mixture to a blender or food processor and puree until smooth. Repeat with the remaining soup.
- To serve the soup cold, transfer it to a bowl, cover, and refrigerate for at least 3 hours and up to 24 hours.
- To serve the soup hot, return it to pan and place over medium heat until warmed through. Ladle into teacups.