Braised Short Rib Shepherd's Pie with Cheddar-Chive Mash

Preheat oven to 325°F (165°C). Pat 2 lb boneless short ribs dry and season generously with salt and pepper. Heat 2 tbsp olive oil in a Dutch oven over medium-high until it shimmers without smoking, then sear the ribs 3-4 minutes per side until deeply browned. Transfer to a plate.

Reduce heat to medium. Add diced onion, carrots, and celery; sweat for 6-8 minutes until the onions turn translucent and edges caramelize. Stir in minced garlic and 2 tbsp tomato paste, cooking 90 seconds until brick-red and fragrant.

Deglaze with 1 cup dry red wine, scraping up the fond, and reduce by half. Add 2 cups beef stock, 1 tbsp Worcestershire, and 2 sprigs fresh thyme. Return ribs to the pot, cover, and braise in the oven for 2.5 hours until the meat shreds easily with a fork.

Meanwhile, boil 2 lb peeled Yukon Gold potatoes in salted water for 18-20 minutes until a knife slides through without resistance. Drain and rice or mash while hot.

Fold 4 tbsp butter, 1/2 cup warm whole milk, 1 cup grated sharp cheddar, and 3 tbsp chopped chives into the potatoes. Season with salt until it tastes vibrant.

Shred the braised ribs, discarding excess fat. Reduce the braising liquid on the stovetop over medium-high for 5-8 minutes until it coats the back of a spoon. Stir the meat back in.

Transfer the filling to a 9x13 baking dish. Spread the mashed potatoes evenly on top, then drag a fork across the surface to create peaks that will crisp.

Increase oven to 400°F (205°C) and bake for 22-25 minutes until the peaks are golden brown and the filling bubbles at the edges. Rest 10 minutes before serving.