Saute the Aromatics: Begin by heating a splash of sunflower oil in a large pot or Dutch oven. Saute the sliced onions and garlic until softened and fragrant, being careful not to burn them.
Add the Vegetables: Next, add the chopped carrots, parsnips, root parsley, kohlrabi, and celeriac root to the pot. Allow them to cook for a few minutes, allowing their flavors to meld together.
Simmer the Broth: Pour enough water into the pot to cover the vegetables completely. Add turmeric, salt, and a handful of parsley stems for extra depth. Bring the pot to a simmer, then reduce the heat and let the broth cook gently for about 30 minutes, or until the vegetables are tender.
Strain the Broth: Once the broth has finished cooking, allow it to cool slightly before straining it through a fine-mesh sieve or cheesecloth. This removes any solids, leaving behind a clear and flavorful broth.
Immediate Enjoyment or Future Use: At this point, you have two options. You can adjust the salt to your taste and enjoy the broth immediately, reveling in its warmth and nourishment. Alternatively, you can cool the broth completely and portion it into containers for future use. Frozen broth can be added to soups, stews, sauces, or risotto, providing instant depth and flavor to your dishes.