– 3 tablespoons olive oil – ½ cup ginger, fresh, peeled and sliced – 1 red onion, large, cubed – 3 sprigs of fresh thyme or ½ teaspoon of dry leaves – 1 carrot, large, peeled and diced – 2 pound celeriac, [0.9 kg], peeled and cubed – 1½ quart vegetable stock, [1½ lt] – 1½ teaspoons salt, (or more, to taste) – ½ teaspoon pepper (freshly-cracked, or ground), (or more, to taste)