Fill a large saucepot with 1 inch of water and place it over high heat. Steam the cauliflower, whole and uncovered, until fork tender, about 15 minutes.

Once the cauliflower is finished cooking, drain the water from the pot. Leave the cauliflower in the hot pot, cover and put back on the stove. Let sit for 5 minutes to help draw out any excess moisture. This is an important step. If you skip this step, you could end up with cauliflower soup.

Fork mash the cauliflower in the pan. Add the garlic, butter, sour cream, Parmesan cheese, chives, mustard, onion flakes, salt and pepper. Mash until the cauliflower reaches a potato-like consistency and all the ingredients are well incorporated.

Preheat the oven to 375°F.

In a large skillet over medium-low heat, heat the butter and olive oil. Add the onion and garlic. Cook until the onion is translucent, and the garlic is fragrant.

Add the ground beef and ground pork. Cook until the meats are browned and drain any excess grease. Add the tomato paste, Worcestershire sauce, oregano, salt and pepper. Sauté for 5 minutes.

Add the carrots and bell pepper to the pan and sauté for 10 minutes. Then mix in the peas.

Transfer the meat mixture to a large casserole dish. Top with a layer of Cheddar cheese.

Spoon the cauliflower mash into a large plastic zip top bag (or pastry bag). Snip off the corner and pipe a thick layer of the cauliflower mash on top of the cheese layer.

Bake for 10 to 15 minutes, or until the top is golden browned and crisped up in places.