Pull chops from the refrigerator at least 30 minutes before cooking — cold meat in a hot pan seizes and cooks unevenly. Pat thoroughly dry with paper towels; moisture kills your sear. Season both sides generously with salt and pepper, then drizzle lightly with olive oil. If marinated, shake off excess and still season with salt. Set a plate nearby for resting after cooking.

Heat a heavy skillet (cast iron preferred) over medium-high for 2–3 minutes until hot. Add a high-smoke-point oil (vegetable or avocado) and swirl to coat — it should shimmer immediately. Lay chops in a single layer with space between them. Don't crowd the pan or they'll steam instead of sear; work in batches if needed. Sear without moving for 3–5 minutes until a deep golden-brown crust forms. If they stick, they're not ready — a proper sear releases naturally. Flip once and sear the second side another 3–5 minutes (6–10 minutes total depending on thickness). Pull at 130°F for medium-rare; 140–145°F for medium. Use an instant-read thermometer inserted into the thickest part away from the bone.

Reduce the heat to medium. Add the 1 large onion roughly chopped and 2 stalks celery sliced into 1-inch pieces to the same pot (with the drippings) and cook, stirring occasionally, for 4–5 minutes until softened and lightly golden.

Add the 3 cloves garlic minced and 2 tbsp tomato paste and stir for 1 minute until fragrant and the paste turns a slightly darker, brick-red color.

Sprinkle the 2 tbsp all-purpose flour for thickening evenly over the onion mixture and stir well to coat, cooking for 1 minute.

Pour in the lamb stock and 1 cup water to cover, scraping up any browned bits from the bottom of the pot with a wooden spoon — those bits are pure flavor. Return the browned 2 ½ lb boneless lamb shoulder or stew meat (along with any resting juices) to the pot.

Add the 2 whole bay leaves, 4 sprigs fresh thyme sprigs, and 1 sprig fresh rosemary (if using). Bring the stew to a boil over high heat, then reduce the heat to low. Cover with a lid slightly ajar and simmer gently for 45 minutes.

Add the 3 medium Yukon Gold potatoes peeled and cut into 1.5-inch chunks, 3 medium carrots peeled and cut into 1-inch pieces, and 1 medium parsnip peeled and cut into 1-inch pieces (if using) to the pot. Stir to submerge them in the broth, adding a splash more 1 cup water to cover if needed to just cover. Continue to simmer, partially covered, for another 35–40 minutes, until the 2 ½ lb boneless lamb shoulder or stew meat is fall-apart tender and the vegetables are completely cooked through.

Remove and discard the 2 whole bay leaves, 4 sprigs fresh thyme sprigs, and 1 sprig fresh rosemary sprig. Taste the broth and adjust seasoning with 1 ½ tsp kosher salt and ½ tsp black pepper freshly ground as needed. If you'd like a thicker stew, use the back of a spoon to lightly mash a few potato chunks against the side of the pot and stir them in.

Ladle into deep bowls, garnish generously with fresh fresh flat-leaf parsley roughly chopped, and serve with crusty soda bread or Irish brown bread for dipping.