Preheat the oven to 350 degrees.

In a pot, boil the cauliflower and broccoli for a few minutes until just beginning to become tender. Rinse immediately under cold water to stop cooking, and drain completely.

Rinse the green beans under warm water to dethaw them, and then toss with the cauliflower and broccoli, and place in the bottom of a 13x9 casserole dish.

In a large skillet over medium-high heat on the stove, heat the olive oil.

Add the chicken thighs (cut into bite sized pieces) to the heated skillet, and add salt and pepper to taste.

Saute until the chicken is almost completely cooked through, and then add in the chopped onion.

Cook for an additional 3-4 minutes, and then add the minced garlic. Saute for another 30 seconds, and remove from the skillet.

Pour the chicken mixture over the vegetables in the casserole dish.

In the same skillet on the stove over medium heat, add the chicken broth to deglaze the pan.

Whisk in the heavy whipping cream, and add salt and pepper to taste.

Continue to cook the cream mixture down until it thickens.

Pour the thickened sauce over the meat and vegetables in the casserole dish, and toss slightly to coat.

In a mixing bowl, add the ingredients for the biscuit topping, and blend until well combined.

Form the biscuit dough into sections of flattened crust, and place it over the top of the mixture in the casserole dish.

Bake for 25-30 minutes until browned and bubbling.

Let sit for several minutes to cool before serving.