Add the oil to a 5 to 6 quart (4.7 L to 5.7 L) stockpot and heat over low-medium heat. Add half of the leek and scallion greens (just eyeball it) and sauté, stirring frequently, for a few minutes until softened. Add parsley, thyme, peppercorns, bay leaf, carrots, remaining leek and scallion greens, potatoes, parsnips, fennel, celery and salt to the pot.
Add enough cold water to cover the vegetables by about 2-inches (5 cm). Cover pot and bring to a simmer over medium heat; adjust heat and cook at a gentle simmer for 1 hour. Skim off any froth that rises to the top during the first half hour. Check occasionally and add water if necessary to keep all solid ingredients just submerged. Taste for flavor. If the broth seems weak, keep simmering for a while. You might also want to adjust salt level.
Strain into a clean pot or storage container(s) and discard solids. Allow broth to cool to room temperature, then refrigerate overnight. Skim all of the fat off of the surface, if desired. Divide the broth into airtight containers in small portions for ease of use. We like to make 1 cup (240 ml) and 2 cup (480 ml) amounts in particular and either refrigerate up to a 3 days or freeze for up to 6 months. You can also freeze the broth in ice cube trays, then pop out the cubes once frozen and freeze in heavy plastic zipper top bags.
If you are not vegan and want to try an extra ingredient that adds tons of flavor, add a big hunk of parmesan cheese rind with the rest of the ingredients during simmering. It adds flavor as well as a little body.
If You Can Tolerate
If you have passed the Onion Fructan Challenge, feel free to use a white or yellow onion or two (to your tolerance) in lieu of the leeks and scallions, and it may be left in during simmering.
If you have passed the Garlic Fructan Challenge, feel free to use minced garlic (to your tolerance), added at the beginning and sautéed, and it may be left in during simmering.
If you have passed the mannitol Challenge consider adding up to 3 stalks of celery. It adds such a wonderful flavor to soup bases.
Low FODMAP Vegetable Broth
Amount Per Serving
Calories 113Calories from Fat 36
% Daily Value*
Saturated Fat 1g5%
* Percent Daily Values are based on a 2000 calorie diet.