Begin by peeling and chopping the russet potatoes into even chunks. In a large pot, cover the potatoes with cold water and add a pinch of salt. Bring it to a boil over medium-high heat, then let simmer for about 15 minutes until fork-tender. Drain the potatoes, return them to the pot, and mash with unsalted butter, sour cream, milk, and a dash of salt until creamy and smooth.

Preheat your oven to 400˚F (200˚C). In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add 1 pound of ground beef, cooking until browned, which should take about 5-7 minutes, breaking it up into small pieces. Stir in diced carrots, celery, onion, and minced garlic, sautéing for another 5 minutes until the veggies soften and release their aromatic fragrance.

Stir in 2 tablespoons of tomato paste and let it cook for a minute to deepen the flavor. Carefully pour in ½ cup of dry red wine, scraping the bottom of the skillet to deglaze and mix in all those flavorful bits. Add a splash of Worcestershire sauce and 1 cup of chicken broth, allowing the mixture to simmer gently for about 5 minutes until it thickens slightly. Finally, fold in 1 cup of frozen peas and season with salt and pepper to taste.

In a greased baking dish, spread the beef and vegetable filling evenly on the bottom, creating a delicious layer of heartiness. Next, spoon the creamy mashed potatoes over the filling, using a fork to create ridges that will crisp up beautifully in the oven. Bake the assembled Easy Classic Shepherd's Pie for 25-30 minutes, or until the top turns a lovely golden brown and appears slightly crisp.

Once baked, remove the shepherd's pie from the oven and allow it to cool for about 10 minutes. This cooling time helps the layers set for easier serving. Garnish with fresh parsley and chives if desired, then serve it warm to your family and watch their faces light up with delight!