Using a heavy bottom soup pot (I use a Le Creuset), heat the olive oil over medium heat. Add the onion, garlic, thyme and a small pinch of salt. Allow them to sweat for 5 minutes, or until soft.
Coat the veggies with flour and stir well. You might see a bit of caramelization on the bottom of the pan, which is a good thing. Stir everything around for a minute or two and then add the chicken stock. Bring the mixture to a boil.
While the stock is heating up, peel and dice the potato. I do this at the last second to avoid discoloration. If you want to peel the potato in advance, leave it in a bowl of water, but don't dice it or you'll lose too much starch. You want that to help thicken the chowder!
Once the stock is boiling, add the half and half as well as the potato. Stir well and allow the mixture to boil for 8 minutes. The potatoes may try to stick to the bottom of the pot so give it a stir periodically.
Slice the kernels off the corn cobs and add to the chowder. Allow the soup to simmer for another 10 minutes or so. Add the salt, pepper, and parsley.