Ideally, you can add all ingredients in the slow cooker except the cornstarch and give it a good mix.
But to ensure everything is well combined and cooks evenly I like to layer things
Start by adding the oil, onions, and garlic (slices and whole)
Followed by the lamb, salt and pepper
In a bowl or measuring cup combine the stock, ketchup, mustard, soy sauce, brown sugar, paprika – stir well then pour over the lamb
Add the bay leaves, rosemary, and thyme
Make sure everything is immersed inside the liquid.
Cover the slow cooker with its lid.
Cook on low for 6 hours or on high for 4 hours or until the meat is fork-tender
After the cooking time – combine the cornstarch with a little water to create a slurry – add it to the slow cooker – stir well.
Continue to cook on low for half-hour or high for 15 minutes.
Discard the leaves before servings.