In a medium saucepan, bring the stock to a boil. Lower the heat. Stir in the chopped mint and simmer for 15 minutes. Stir in the peas and simmer for 8 to 10 minutes, until tender. Remove from the heat and drain in a fine-mesh sieve, reserving both the solids and the liquid.
In a food processor, purée the peas and mint, scraping down the sides as necessary. Add 114 to 2 tablespoons of th