Preheat an oven to 350 degrees.
In a small oven-safe pan add 6 cloves of peeled garlic. Drizzle with olive oil and a small pinch of salt.
Roast the garlic in the oven for approximately 8-9 minutes or until the cloves of garlic are soft and slightly dark brown, but not black. The cloves should be soft, not hard and crunchy.
Remove garlic from the oven and place on a cutting board. Place the flat side of a knife over the garlic and press down on the the knife to smash the garlic against the side of the knife (being careful to avoid the blade). Do this with all of the garlic cloves. Briefly chop the garlic. It should be very soft, like a paste.
In a heavy pot add the chicken stock, thyme, smashed roasted garlic, heavy cream and cayenne. Bring the liquid just to a boil and add the polenta. With a whisk, stir in the polenta vigorously until incorporated. The polenta should absorb the liquid fairly quickly.
While continuing to whisk, add the Monterrey Jack cheese and Parmesan (optional). Since the cheese contains salt, taste the polenta before you add additional salt.
Once the cheese has melted into the polenta, add a pat of butter or drizzle with olive oil on top. Cover and reserve until needed. The butter or olive oil will help keep a skin from forming on top of the polenta while it is resting. You can also accomplish this with a little water if you do not wish to add butter or oil.
The polenta is ready to be served.