Ingredients

1. 2 1/2 tablespoons unsalted butter
2. 1/2 small onion, finely chopped
3. Two 10-ounce packages frozen peas
4. 1/2 cup chicken stock or canned low-sodium broth
5. Salt and freshly ground pepper
6. 2 tablespoons finely chopped mint

Directions

1. Melt 1/2 tablespoon of the butter in a medium saucepan. Add the onion and cook over moderate heat, stirring occasionally, until softened but not browned, about 3 minutes. Add the peas and stock and season with salt and pepper. Simmer over low heat for 15 minutes. Transfer the pea mixture to a food processor and puree until smooth. Return the puree to the pan and beat in the remaining 2 tablespoons of butter and the mint.

Make Ahead

The puree can be made while the batter for the Batter-Fried Cod with Minted Pea Puree is fermenting. Reheat it, then stir in the butter and mint before serving.