01 -
Okay, first things first, get those potatoes peeled and chopped into even chunks. Toss them into a big pot with some cold, salted water – this is where I always forget to salt the water, oops! Bring 'em to a boil, then simmer until they're fork-tender, about 15-20 minutes. Drain really well, then mash 'em up with your butter and warm milk. Season with salt and pepper. I like mine a bit lumpy, gives it character, you know? Set aside.
02 -
While your potatoes are doing their thing, grab a large, oven-safe skillet (or a large pot). Melt a tablespoon of butter or heat olive oil over medium heat. Add your chopped onion, carrots, and celery. Sauté them until they start to soften and smell amazing, about 5-7 minutes. Don't rush this step; building flavor here is key, honestly. Sometimes I let them get a little bit of color, adds depth.
03 -
Sprinkle the flour over your softened veggies and stir it around for a minute or two. This is going to thicken our sauce. Pour in the chicken broth and Worcestershire sauce, then stir continuously until it thickens up a bit, about 2-3 minutes. It should be a nice, gravy-like consistency.
04 -
Now, stir in your shredded rotisserie chicken, dried thyme, and those thawed frozen mixed vegetables. Let it all simmer gently for about 5 minutes, allowing the flavors to meld beautifully. It'll smell so good, you'll want to dig in right then! Make sure everything is heated through.
05 -
Taste your filling and adjust the salt and pepper as needed. Transfer the chicken filling to a 9x13 inch baking dish if your skillet isn't oven-safe. Carefully spoon the mashed potatoes over the filling, spreading it evenly to cover everything. You can get fancy with a fork to create little ridges, or just spread it rustic-style like I do. Sprinkle with cheddar cheese, if using.
06 -
Pop your assembled <span class="highlight">Rotisserie Chicken Shepherd's Pie</span> into a preheated oven at 375°F (190°C) for about 20-25 minutes, or until the filling is bubbly and the mashed potato topping is golden brown and slightly crispy. If you want it extra crispy on top, you can broil it for a minute or two at the end, but watch it like a hawk! Let it rest for a few minutes before serving. It smells absolutely divine when it comes out!