Remove kernels from the cob and set aside in a bowl. Save the cob for later.
In a small pot, heat oil and add yellow onions, garlic and thyme. Sautee until fragrant.
Add the vegetable stock, bay leaves and cobs of corn to the pot, bring to a boil.
Cover and reduce to a simmer for 20 to 30 minutes.
Remove the 12 cobs, allow to cool and with the back of a kitchen knife scrape the corn "milk" from the cob.
Reserve and place the liquid back into the pot along with the corn kernels.
Simmer corn for another 10 to 15 minutes or until stock is reduced by half.
Remove the thyme sprigs and puree half the mixture, add puree back to the pot.
Adjust seasoning with salt and serve.