Preheat your oven to 400°F and prepare a small individual baking dish.
Steam the cauliflower florets and diced potato in a steamer basket over boiling water until very tender, about 10 to 12 minutes.
While the vegetables steam, heat the olive oil in a large skillet over medium heat and sauté the onion and carrots until they begin to soften.
Add the ground beef to the skillet, breaking it apart with a wooden spoon, and cook until it is fully browned and no pink remains.
Stir in the tomato paste, beef broth, dried thyme, sea salt, and black pepper, then simmer for 5 minutes until the sauce thickens into a gravy.
Fold in the frozen peas and remove the skillet from the heat.
Drain the steamed cauliflower and potato well, then mash them thoroughly with the ghee until the mixture is smooth and velvety.
Transfer the beef and vegetable mixture into the baking dish and spread the cauliflower mash evenly over the top.
Bake for 10 minutes, then switch the oven to broil for 2 to 3 minutes until the top is golden brown and bubbling.