Method
1. Peel and finely slice the onions. Set a frying pan on a medium-low heat and drizzle in a little oil. Add the onions and season well with salt and pepper. Pop a lid on the pan (or use a baking tray if you don't have a lid) and sweat the onions for 10 mins, stirring often, till they are soft, glossy and browned.
2. While the onions fry, trim and peel the carrots, then slice into rounds around 2cm thick. Peel the potatoes and thinly slice 1 of the potatoes, so it's just a few mm thick (this will break down in the slow cooker and thicken the stew). Chop the rest into chunks around 3-4cm across.
3. When the onions have browned, scoop them into your slow cooker and add the chopped carrots and potatoes. Set the pan aside, off the heat.
4. Rub a little salt and pepper into the lamb neck fillet, then chop into 8 rounds about 1cm thick. Pop the frying pan on a medium-high heat and drizzle in a little oil. Add the lamb neck and fry, turning often, for 2-3 mins till browned all over. Add the lamb to the slow cooker.
5. If you have heatproof kitchen string, tie the bouquet garni into a bundle, then drop it into the slow cooker. If not, just add the herbs to the cooker. Tying them into a bundle just helps fish them out at the end. Pour in the chicken stock. Set your slow cooker to high and cook for 6 hrs, till the lamb is very tender and the veg are soft. For a faster stew, set to high and cook for 4 hrs. For a slower cook, set to low and cook for 7-8 hrs.
6. Lift out the bouquet garni herbs and discard them. Taste the lamb stew and add a pinch more salt and pepper, if you think it needs it. Ladle the stew into warm bowls. Tear or chop the flat leaf parsley leaves and scatter over the stew to garnish. Serve straight away.
7. Eat Me, Keep Me
The stew will keep for up to 3 days in the fridge in a sealed tub. You can also freeze it for up to 3 months. Ladle into freezerproof tubs, let the stew cool, then seal and chill. Defrost overnight in the fridge and warm through on the hob or in the microwave till piping hot.