Preheat the oven to 350 degrees.
Melt the butter in a pot over medium heat.
Add in the onions, and saute until softened.
Stir in the garlic, and saute for 30 seconds.
Mix in the mustard powder, paprika and cream cheese. Stir until the cream cheese has melted.
Slowly stir in the heavy whipping cream, whisking as you do.
Simmer until the sauce thickens.
Add 1 cup of the cheddar cheese to the sauce, and stir until melted.
Season with salt and pepper to taste.
In a large mixing bowl, combine the cauliflower rice, broccoli and ham.
Pour the cheese sauce over the ingredients in the mixing bowl. Stir to combine well.
Spread the mixture into a well greased 9x13 baking dish.
Sprinkle with the remaining cheese.
Bake for 20-25 minutes.
Allow to sit 10 minutes before serving.