Part 1: Prepare the Cauliflower Topping

1. Cook the Cauliflower: Place the cauliflower florets in a large pot. Add about an inch of water, cover, and bring to a boil. Reduce heat to medium and steam for 10-15 minutes, or until the cauliflower is very tender and easily pierced with a fork. Alternatively, you can steam it in a microwave-safe bowl with a little water, covered, for 8-12 minutes.
2. Drain Thoroughly: Once tender, drain the cauliflower very well. This is crucial to avoid a watery topping. You can even pat the florets dry with paper towels or return them to the hot pot for a minute over low heat to evaporate excess moisture.
3. Mash the Cauliflower: Transfer the drained cauliflower to a large bowl or back into the dry pot. Add the butter, softened cream cheese, heavy cream, Parmesan cheese, garlic powder, salt, pepper, and optional nutmeg.
4. Blend to Smoothness: Use an immersion blender to blend the cauliflower mixture until smooth and creamy. You can also use a food processor (work in batches if necessary) or a traditional potato masher, though an immersion blender or food processor yields the smoothest results. Avoid over-processing, which can make it gummy.
5. Incorporate Cheese: Stir in 1/2 cup of the shredded cheddar cheese into the warm cauliflower mash. Taste and adjust seasonings if needed. Set aside.

Part 2: Cook the Meat Filling

1. Sauté Aromatics: Heat the olive oil (or chosen fat) in a large, deep skillet or Dutch oven over medium-high heat. Add the chopped onion, celery, and carrot (if using). Sauté for 5-7 minutes, until softened and the onion is translucent.
2. Add Garlic: Stir in the minced garlic and cook for another minute until fragrant, being careful not to burn it.
3. Brown the Meat: Add the ground lamb or beef to the skillet. Break it up with a spoon and cook, stirring occasionally, until browned all over (about 8-10 minutes). Drain off any excess fat if there’s a lot.
4. Build Flavor: Stir in the tomato paste and cook for 2-3 minutes, allowing it to caramelize slightly. This deepens the flavor. Add the Worcestershire sauce (or coconut aminos), dried rosemary, and dried thyme. Stir well to combine.
5. Deglaze & Simmer (if using wine): If using red wine, pour it into the skillet and scrape up any browned bits from the bottom of the pan. Let it simmer for 2-3 minutes, allowing the alcohol to cook off and the liquid to reduce slightly.
6. Add Broth & Thicken: Pour in the beef broth. If using xanthan gum for a thicker gravy, sprinkle it evenly over the meat mixture now and stir vigorously to incorporate without lumps. Bring the mixture to a gentle simmer.
7. Simmer to Perfection: Reduce the heat to low, cover, and let the meat filling simmer for at least 15-20 minutes (or up to 30 minutes for even deeper flavor), allowing the flavors to meld and the sauce to thicken. If it becomes too thick, add a splash more broth.
8. Stir in Vegetables: If using frozen peas or chopped mushrooms, stir them into the meat filling during the last 5-10 minutes of simmering, until heated through.
9. Taste and Adjust: Season the meat filling with salt and black pepper to your taste. Remember, the cauliflower topping will also be seasoned, so aim for a well-balanced flavor.

Part 3: Assemble and Bake Your Keto Shepherd’s Pie

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Layer the Filling: Pour the prepared meat filling into a 9×13 inch baking dish or a similar-sized oven-safe casserole dish. Spread it out into an even layer.
3. Top with Cauliflower Mash: Carefully spoon the prepared cauliflower mash over the meat filling. Spread it gently to cover the meat completely, sealing the edges if possible to prevent the filling from bubbling over too much. You can create a rustic, swirled pattern with the back of a spoon or use a fork to create ridges, which will crisp up nicely.
4. Add Remaining Cheese: Sprinkle the remaining 1/2 cup of shredded cheddar cheese evenly over the cauliflower topping.
5. Bake to Golden Perfection: Place the baking dish in the preheated oven. Bake for 25-30 minutes, or until the topping is golden brown and the filling is bubbly around the edges. If the topping starts to brown too quickly, you can loosely tent it with aluminum foil.
6. Rest Before Serving: Once baked, remove the Keto Shepherd’s Pie from the oven and let it rest for 10-15 minutes before serving. This allows the filling to set slightly and makes it easier to serve. It will also be very hot!