- Cut an onion in half from tip to the hairy end and peel. Cut the onion halves into thin slices then cut the slices into thin strips to make small cubes. Place in a small bowl.
- Peel the celery root and cut into small cubes. Add to the onion. (If using celery, cut into small cubes).
- Peel the garlic cloves, cut into small slices and add to the bowl.
- Run your fingers down fresh thyme stems to remove the leaves. Add the onion bowl.
- Wash and scrub the potatoes. Cut potatoes in ½ then cut into cubes. Place in another small bowl.
- Break the husked corn cobs in half. Stand the corn cob pieces up on the cutting board and carefully cut the kernels off the cob by cutting down on the cob. Add to the potatoes.
- Place a large pot (like a Dutch oven) on the stove top and turn on the heat to a medium heat. Add the butter and allow it to melt.
- Add the onion mixture and sauté until onions are translucent, about 5 minutes.
- Add the stock, potatoes and corn, salt and pepper.
- Bring to a boil then reduce the heat and simmer for about 20 minutes, until potatoes are soft.
- Add the cream, stir and heat through.
- Serve in warmed bowls.
You can make corn cob stock ahead of time and use instead of chicken or vegetable stock. Combine the leftover corn cobs with 8 cups (2 liters) of water, 1 tsp. salt, a sprig of thyme and bay leaf in a large pot and place over medium heat. Bring to a boil then turn the heat down and simmer the stock for 1 hour. Strain through a fine mesh strainer, throwing out the solids.