Preheat oven to 350°F.
Salt and pepper the six 6 small boneless and skinless chicken breasts on both sides.
Heat a heavy-bottomed skillet over medium-high. Add one tablespoon of olive oil until hot.
Add the chicken to the skillet and cook for about three minutes on each side. They should have a golden brown sear on them.
Place the skillet in the oven and cook for 20-25 minutes or until an internal thermometer reads 160°F in the thickest part of the chicken breasts.
Remove them from the skillet, cover with foil, and set aside. The chicken will continue to cook to the desired 165°F while resting.
While the chicken is cooking, add the florets of two medium heads of cauliflower to a large pan with 8 cups of chicken stock. (You can use water if you would like.)
Bring to a boil over medium-high heat. Turn the heat down to a simmer and cook for 20 minutes or until tender, not mushy.
Drain the cauliflower well and place into a food processor. Depending on how thick it is when puréed, add a ⅛ to ¼ cup half and half and 2 tablespoons butter. Purée until it is smooth. If it is still too thick add a little bit of the cooking liquid.
Using the same skillet used for the chicken, heat it over medium-high heat. When hot add one tablespoon of olive oil.
Add one large chopped sweet onion to the skillet and turn the heat down to medium.
Sauté the onion for about 5 minutes, stirring frequently, until it is slightly tender.
Turn the heat to medium-high again and add one pound of sliced baby bella mushrooms. Stir occasionally and cook for 8-10 minutes, until nice and brown with a caramelization.
Add in 6 large minced garlic cloves. Cook for 30 seconds to 1 minute until you can fully smell its aroma.
Pour the puréed cauliflower into the skillet and stir to combine the cauliflower, onions and mushrooms.
Season with kosher salt and freshly ground black pepper, to taste.
Stir in 8-10 ounces of cooked fettuccini.
Garnish with fresh chopped thyme.
Slice the chicken breasts and add alongside the pasta dish or dice the chicken and add it into the dish along with the pasta.
