1. In a small bowl, cover cashews with boiling water and set aside to soften. In a small pot, add brown lentils, cover with water and cook until tender in approximately 20 minutes. Peel and chop potatoes in bite-sized pieces, chop onion, celeriac, carrot and garlic in cubes.
2. Add peeled and chopped potatoes and celeriac to a large pot and cover with cold water. Bring to a boil over high heat. Then reduce heat and simmer potatoes for 10-15 minutes, or until they are tender. Drain and set aside.
3. Add cashews and draining water to a blender and blend until creamy. Add ¼ to ⅓ of the boiled potatoes and celeriac (depending on your desired consistency) and blend.
4. In the same pot used to boil the potatoes, add oil, onions, garlic carrots, and salt. Cover and cook over low heat until tender. Do not brown.
5. Turn heat to medium and add the vegetable stock and water. Stir in the blended cashew/potato mixture. Add the chopped potatoes and celeriac as well as the lentils. Cook on medium-low for 5 minutes.
6. If desired, adjust consistency with water or vegetable broth. Adjust seasoning, adding nutritional yeast flakes, salt, pepper to taste. Enjoy!