Chop the cauliflower and add it to a pot of water. Bring the pot to a full boil and cook until cauliflower is very soft, about 8 to 10 minutes. Strain the cauliflower, then transfer it to a blender along with the butter, garlic and sea salt.  Blend until cauliflower reaches desired consistency. Note: You may need to stop the blender a few times, scrape the sides and re-start.

(note: if you have a potato masher, you can mash the cauliflower in the same pot you used for cooking instead of blending it). Taste the cauliflower for flavor and add sea salt or butter to taste.

Add the avocado oil to a large non-stick skillet and add the onion. Sauté, stirring occasionally, until the onion begins to brown, about 5 to 8 minutes.

Add the ground beef and use a spatula to chop it into smaller bits. Stir in the garlic, parsley, oregano, sea salt, and carrots then cover the skillet and cook until carrots soften up, about 3 to 5 minutes.

Add the remaining ingredients to the skillet and stir well. Continue cooking, stirring occasionally, until the sauce around the meat has thickened, about 5 to 8 minutes.

Spread the meat mixture in the bottom of a 9 or 10-inch pie dish (or medium-sized casserole dish).

Transfer the mashed cauliflower over the meat mixture and spread evenly.

Bake in the preheated oven until cauliflower mash begins to turn golden-brown and meat mixture is bubbly, about 35 to 45 minutes.

Remove Cottage Pie from the oven and serve.