Heat oven to 325°. In a deep casserole dish (or cast iron skillet) brown the lamb in the butter and oil and seasoning with salt, pepper, and thyme. Remove from heat and set aside (lamb will finish cooking in oven)

Add carrots and onions to skillet and add a tsp beef broth here and there to prevent from burning (deglaze) Lightly season (because the beef broth has a a lot of sodium)

Once onions are carmelized add the lamb back and sprinkle 4 tbsp of flour over the mixture. Mix then add the beef broth. Bring to a simmer til it thickens. Add Worcestershire sauce, and stir well.

Cover with foil and place in oven for 30 min

Remove from oven and add remaining 4 tbsp of flour to thicken. Whisk in quickly and add potatoes sliced on top. Brush with 1 tbsp melted butter with salt and pepper added to it. Sprinkle thyme on top. Recover and bake for another hour.

Remove foil and turn oven up to 400° and bake for another 40 min. Garnish with parsley!