• Prepare the Cauliflower Cream Sauce: 
• Heat a large pot of water on the stove top and bring it to a full boil. Add the chopped cauliflower and onion and cook until the cauliflower is very tender, about 8 to 10 minutes. 
• Strain the cauliflower and onion into a colander, then transfer to a high powered blender. Add the remaining ingredients for the cauliflower sauce to the blender and blend until completely smooth. Set aside until ready to use. 
• Note: This portion of the recipe can easily be made up to 3 days ahead of time. Simply store the sauce in an air-tight container in the refrigerator until you’re ready to use it.

Prepare the Meat Sauce:

• Heat the avocado oil in a large non-stick skillet over medium-high heat. Add the onion and saute, stirring occasionally, until the onion begins to turn golden-brown, about 5 to 8 minutes.
• Scoot the onion off to one side of the skillet and add the ground beef. Allow the beef to brown for 2 to 3 minutes, then flip to the other side and allow it to brown another 2 to 3 minutes. Use a spatula to chop up the meat into smaller chunks, then add the rest of the ingredients for the sauce to the skillet. Bring the sauce to a full boil. Cover and reduce the heat to a gentle boil. Cook for 10 minutes (or up to 50 minutes at very low heat if you have the time), stirring occasionally.
• Cook the Noodles: 
• While the sauce is cooking, cook the noodles according to the instructions on the package. Strain into a colander then immediately run cold water over the noodles. This removed excess starch and also stops the cooking process.

Make the Casserole:

• Preheat the oven to 375 degrees F.
• Transfer the cooked noodles to a large (13” x 9”) casserole dish, followed by the meat sauce. Gently stir until the noodles are well-coated in sauce.
• Pour the creamy cauliflower sauce over the casserole and smooth into an even layer.
• Bake for 20 to 25 minutes or until the cauliflower sauce has a golden-brown hue to it.
• Allow the baked ziti to cool for 10 minutes before serving.