1. Cook the Potatoes and Garlic:

Place the cubed potatoes and halved garlic cloves in a large pot.

Cover with cold, salted water. Bring to a boil over high heat.

Reduce the heat to medium-low, cover, and simmer until the potatoes are very tender, about 20 minutes.

2. Preheat the Oven and Brown the Beef (Properly!):

While the potatoes are cooking, preheat your oven to 375 degrees F (190 degrees C).

Heat a large skillet over medium-high heat. Add the ground beef and cook, breaking it up with a spoon or spatula.

Crucially, cook the beef in batches if necessary. You want to get good browning on the beef, which won’t happen if the pan is overcrowded. Remove the browned beef to a plate and drain off any excess grease, leaving about 1 tablespoon in the pan.

3. Build the Flavor Base: If needed add a drizzle of oil.

Add the flour to the skillet and cook, stirring constantly, for about 1 minute. This creates a roux that will thicken the sauce.

Stir in the frozen (or fresh) mixed vegetables, beef broth, ketchup, Worcestershire sauce, thyme, salt, and black pepper.

Bring the mixture to a simmer, stirring until the sauce is slightly thickened, about 5 minutes.

4. Transfer to Baking Dish:

Pour the beef mixture into an oven-proof casserole dish (approximately 9×13 inches).

5. Make the Ultimate Creamy Mashed Potatoes:

Drain the cooked potatoes and garlic well. Return them to the pot.

Add the sour cream and half (¼ cup) of the shredded Cheddar cheese to the potatoes.

Mash the potatoes until smooth and creamy. You can use a potato masher, a ricer, or even an electric mixer (but be careful not to overmix). Season with salt and pepper.

6. Assemble the Cottage Pie:

Top the beef mixture in the casserole dish with the mashed potatoes.

Spread the potatoes evenly over the filling, from the center of the casserole to the edges, creating a complete top layer.

Sprinkle the remaining ¼ cup of shredded Cheddar cheese over the top of the mashed potatoes.

7. Bake:

Bake in the preheated oven for 20 to 25 minutes, or until the cheese is melted and golden brown and the filling is bubbling around the edges.

8. Cool and Serve:

Let the Cottage Pie cool for at least 15 minutes before serving. This allows the filling to set slightly and makes it easier to serve. Enjoy!