Ingredients:
- 3 lbs Potatoes (Russet or Maris Piper)
- 4 Tbsp Unsalted Butter, softened
- 1/2 cup Whole Milk or Heavy Cream, warmed
- 1 cup Mature Cheddar Cheese, grated
- Salt and Black Pepper, to taste
- 2 Tbsp Olive Oil or Neutral Oil
- 2 lbs Ground Beef (85/15 recommended)
- 1 large Yellow Onion, finely diced
- 2 medium Carrots, peeled and diced
- 2 stalks Celery, finely diced
- 3 cloves Garlic, minced
- 2 Tbsp All-Purpose Flour
- 1 Tbsp Tomato Purée (Paste)
- 3 cups Beef Stock (low sodium), hot
- 1 Tbsp Worcestershire Sauce
- 1 tsp Dried Thyme
- 1 Bay Leaf
Instructions:
- Prepare the Potato Topping: Peel and dice the potatoes into equal-sized chunks. Place them in a pot, cover with cold, salted water, and bring to a rolling boil. Cook until fork-tender (about 15-20 minutes). Drain the potatoes completely, return them to the hot pot, and let sit for 1 minute to steam off excess moisture.
- Make the Mash: Mash the potatoes until smooth. Incorporate the butter, warmed milk/cream, 3/4 cup of the grated cheddar, salt, and pepper. Set aside.
- Sauté Aromatics: Preheat a large pot over medium heat with oil. Add the diced onion, carrots, and celery (mirepoix). Cook gently until soft and translucent, about 8-10 minutes. Stir in the minced garlic for the last minute.
- Brown the Beef: Increase heat to medium-high. Add the ground beef. Break it up and cook thoroughly until nicely browned, draining off any excessive fat.
- Build the Gravy Base: Stir in the tomato purée and cook for 1 minute. Sprinkle the flour over the meat and vegetables and stir constantly for 2 minutes to cook out the raw flour taste.
- Simmer: Pour in the hot beef stock and Worcestershire sauce, scraping up any browned bits. Add the thyme and bay leaf. Bring to a simmer, then reduce heat to low and cook uncovered for 10 minutes until the sauce is rich and thickened.
- Taste and Adjust: Remove the bay leaf. Season the filling robustly with salt and pepper to taste.
- Assemble the Casserole: Preheat the oven to 375°F (190°C). Pour the beef filling into a prepared 9x13 inch casserole dish, spreading it evenly.
- Top and Finish: Spoon or pipe the mashed potatoes over the filling, ensuring it is completely covered and sealed. Sprinkle the remaining 1/4 cup of grated Cheddar cheese over the potato topping.
- Bake and Rest: Bake for 30–35 minutes, or until the filling is bubbling hot and the potato topping is gloriously golden brown. Let the casserole rest for 10 minutes before serving.