To prepare the mushrooms, trim the ends and cut them in half depending on size.
Preheat oven to 400°F.
Heat an oven proof cast iron casserole over medium heat with the canola oil. Add the minced shallot and garlic and lightly sauté until soft. Add the prepared mushrooms and season to taste with salt and pepper. Add the butter and roast the mushrooms until tender and lightly browned about 10-15 minutes.
Remove the casserole form the oven; place the pan on medium high heat and add the chicken stock. Reduce the chicken stock enough to glaze the mushrooms; add the herbs to the mushrooms and adjust the seasoning.