This soup traditionally uses "salted herbs," a Quebec specialty. To make them: In a large bowl, combine 1 cup chopped fresh chives, 1 cup chopped fresh savory, 1 cup chopped fresh parsley, 1 cup chopped fresh chervil, 1 cup grated carrots, 1 cup chopped celery leaves, and 1 cup chopped green onions. Layer 1 inch (2.5 cm) of the herb/vegetable mixture in the bottom of a crock or glass bowl and sprinkle with some coarse salt (use 1/4 to 1/2 cup total). Repeat layers until all mixture and salt are used. Cover and refrigerate for 2 weeks. Drain off accumulated liquid and pack the herb mixture into sterilized jars. Refrigerate until ready to use. They can be found in Montreal specialty stores or made at home.
This soup freezes well. Allow to cool completely before transferring to airtight containers.
In summer, fresh herbs can be added at the end of cooking instead of using the preserved salted herbs for a brighter flavor.