Let’s get cooking! Here’s a detailed, step-by-step guide:

Step 1: Season and Brown Lamb

Season the lamb shoulder chops generously with salt and black pepper.

Heat the vegetable oil in a large, heavy skillet over high heat.

Working in batches, cook the lamb shoulder chops until browned on both sides, about 3 to 5 minutes per side. Don’t overcrowd the pan; this will prevent the lamb from browning properly.

Transfer the browned lamb chops to a stock pot or Dutch oven.

Step 2: Sauté Onions and Make Roux

Reduce the heat to medium. Add the chopped onion and a pinch of salt to the same skillet (there should be some rendered fat from the lamb; if not, add a little more oil).

Cook and stir the onion until slightly softened and the edges are browning, about 5 minutes.

Stir in the butter until melted.

Add the flour and stir until the onions are coated, about 1 minute. This creates a simple roux that will help to thicken the broth.

Step 3: Add Stock and Rosemary

Pour the chicken stock into the onion mixture.

Bring to a boil, stirring constantly, until the mixture thickens, 5 to 10 minutes.

Add the dried rosemary.

Step 4: Combine and Simmer

Stir the chopped carrots and celery into the pot with the lamb shoulder chops.

Pour the chicken stock mixture (from the skillet) over the top.

Add water as needed to cover the meat completely.

Bring the mixture to a simmer, then reduce the heat to low, cover the pot with a lid, and cook until the meat is almost falling off the bone, about 1 1/2 hours.

Step 5: Add Potatoes

Transfer the meat to a plate using a slotted spoon.

Stir the baby Dutch yellow potatoes into the stew.

Return the meat to the stew, placing it on top of the vegetables.

Simmer, covered, until the potatoes are tender and the meat is falling off the bone, about 30 minutes.

Step 6: Reduce and Thicken (Optional)

Transfer the meat to a plate using a slotted spoon.

Bring the stew to a boil and cook, skimming off any fat that rises to the surface, until the stew is reduced and thickened to your liking, 10 to 12 minutes.

Step 7: Shred Meat and Return to Stew

Remove the meat from the bones and discard the bones and any large pieces of fat.

Stir the meat back into the stew.

Step 8: Finish and Serve

Stir in the green onions.

Season the stew with salt and pepper to taste.

Serve hot, in bowls.

Enjoy this hearty and flavorful Irish Stew!