Heat a large pot with oil. Sauté the minced onion and garlic for 3 minutes.
Add cubed celeriac and apples, sauté for another 3 minutes.
Deglaze with vegetable broth, bring to a boil, cover and simmer for 15-20 minutes until the celeriac is tender. Stir occasionally.
Blend the soup in a high-speed blender, or with a hand blender, until creamy. → Depending on how creamy/liquid you like your soup, add a little more water or vegetable broth.
Return soup to the pot, season to taste with salt and pepper. → Optional: Decorate the soup with chopped parsley, chives, or croutons.
Notes
Apple: The apples give this soup a wonderful sweet and sour note. I used Braeburn apples. Instead of apples, you can also use pears, or 1 apple and 1 pear.
Make-Ahead: Keeps fresh for 5 days. Store it in an airtight container in the refrigerator.Reheat the soup either in the microwave for a few minutes, or heat it in a pot on the stove over medium heat. The soup may thicken up slightly in the fridge, but it usually liquefies again when it’s warmed up. If it’s still too thick, add some extra water.Freeze: Can be frozen for up to 3 months. Thaw it directly in a pot over medium heat.