Place lamb in slow cooker or on work surface. Sprinkle with salt, pepper, thyme or rosemary and garlic. Drizzle over oil, then rub on both sides.

Pour beef stock into slow cooker, add sprig of rosemary (if using).

SLOW COOK on low for 10 hours, or pressure cook on high for 1 hour 40 minutes. (See oven version here)

The lamb should be tender enough to pull off with tongs, but still holding together (just!). Carefully remove lamb from slow cooker and transfer to tray.

Drizzle lightly with oil (any). Bake at 200C/390F for 20 minutes or until browned. Remove and rest for 10 minutes before serving with gravy.

Strain liquid in slow cooker into a bowl - you will have more than the 2 cups of broth you added, I usually have over 3 cups. Measure out 2 cups of liquid, reserve remaining liquid just in case.

Melt butter in a saucepan over medium heat. Add flour and cook for 1 minute.

Add a bit of liquid, mixing as you go so it dissolves. Then add remaining liquid. Whisk if there are lumps.

Increase to medium high heat and cook, stirring regularly, until thickened to your taste. Use remaining liquid to thin if required.