Start by peeling and cutting Yukon Gold potatoes into even chunks. Place them in a large pot, cover with cold water, and add a pinch of salt. Boil for about 15–20 minutes or until fork-tender. Drain well and return to the pot. Mash the potatoes with butter, milk, Greek yogurt, salt, and pepper. Stir in the egg yolk and parmesan for extra creaminess.

In a large skillet, heat a drizzle of olive oil over medium heat. Add diced onions and chopped carrots, sautéing for about 5–7 minutes until softened and fragrant. Next, incorporate the lean ground beef, crumbling it with a wooden spoon as it cooks. Season the mixture with salt, pepper, minced garlic, and smoked paprika, cooking for an additional 5 minutes until the beef is browned.

Sprinkle the beef mixture with all-purpose flour, stirring to coat the meat evenly. Gradually pour in low-sodium beef broth and add tomato paste, mixing until well combined. Allow the filling to simmer for about 5 minutes until thickened and bubbly. Gently fold in the frozen peas for added color and sweetness, allowing them to heat through.

Preheat your oven to 375°F (190°C). In a baking dish, spread the savory beef filling evenly across the bottom. Carefully dollop the creamy mashed potato topping over the beef, smoothing it out with a spatula for an even layer. Bake for 25–30 minutes or until the top is golden and the filling is hot and bubbling. If desired, broil for an extra 2–3 minutes for a crispy finish.

Once baked, remove the shepherd’s pie from the oven and let it cool for about 10 minutes before serving. This resting period allows the layers to set for easy slicing. Serve warm, pairing it with a green salad or crusty bread for a complete, hearty meal that the whole family will love.