Preheat your oven on medium heat to 350°F (175°C).
In a large mixing bowl, combine the heavy cream, cream cheese, and sour cream. Mix until smooth.
Add the garlic powder, salt, and pepper to the cream mixture. Stir well.
Fold in the cauliflower florets, broccoli florets, diced ham, and 1 1/2 cups of shredded cheese.
Transfer the mixture to a greased casserole dish.
Sprinkle the remaining 1/2 cup of cheese on top.
Bake for 30-35 minutes or until the cheese is bubbly and golden.
Garnish with chopped green onions before serving.
Pressure Cooker or Slow Cooker Method
For the slow cooker: Cook on low for 4-5 hours or on high for 2-3 hours.
For the pressure cooker: Cook on high pressure for 5 minutes, then quick release. I love making this in my Instant Pot Duo, it just makes things so much faster especially when everyone is starving.