Step 1: Preheat the Oven

1. Preheat your oven to 400°F (204°C) to prepare for baking.

Step 2: Cook the Potatoes and Cauliflower

1. Place the potatoes in a medium saucepan and cover with water by about 2 inches.
2. Add 2 teaspoons of salt to the water and bring to a boil over high heat.
3. After boiling for 3 minutes, add the cauliflower florets.
4. Cook until both the potatoes and cauliflower are fork-tender, about 4–6 more minutes.
5. Drain well and return to the pot.

Step 3: Make the Creamy Mash

1. Add olive oil, milk, salt, and a few grinds of black pepper to the pot with the drained vegetables.
2. Mash with a potato masher until smooth and creamy. Adjust seasoning if needed.

Step 4: Cook the Vegetables and Beef

1. Heat olive oil in a large skillet over medium-high heat.
2. Add the onion, carrots, and celery, cooking until softened, about 4 minutes.
3. Stir in the garlic and thyme, cooking for an additional minute.
4. Add the ground beef, salt, and pepper. Sauté until browned and crumbled, about 6–8 minutes.

Step 5: Create the Filling

1. Add the peas, tomato paste, red wine (or chicken broth), chicken broth, and Worcestershire sauce to the skillet.
2. Stir well and let simmer for 10 minutes, allowing the flavors to meld and the liquid to reduce slightly.
3. Taste the mixture and adjust the seasoning if necessary.

Step 6: Assemble the Shepherd’s Pie

1. Spread the beef and vegetable mixture evenly in a baking dish (8-inch square or 1.5-quart size works best).
2. Spoon the creamy potato-cauliflower mash over the filling, spreading it evenly to cover.
3. Sprinkle cheddar cheese over the top, if desired.

Step 7: Bake and Serve

1. 1. Place the baking dish on a baking sheet to catch any drips.
   2. Bake in the preheated oven for 25 minutes, or until the filling bubbles and the top is lightly browned.
   3. For extra browning, broil for 1–2 minutes.
   4. Remove from the oven, let cool slightly, and serve warm.