Creating the aromatic and tender Slow Cooker Lamb Curry is a straightforward process if you follow these steps:

1. Prepare the Lamb: Start by cutting the lamb shoulder into 1-inch pieces. Pat them dry with paper towels.
2. Sauté Onions: In a skillet, heat a little oil over medium heat. Add the diced onions and sauté until they become translucent.
3. Add Aromatics: Stir in the minced garlic and ginger, cooking for an additional 1-2 minutes until fragrant.
4. Combine Spices: Mix in the curry powder, ground cumin, ground coriander, turmeric, and chili powder. Cook for another minute to toast the spices.
5. Transfer to Slow Cooker: Pour the onion and spice mixture into your slow cooker. Add the lamb pieces, ensuring they are coated in the spices.
6. Add Liquid Ingredients: Pour in the coconut milk and diced tomatoes, mixing well to combine.
7. Season: Add Worcestershire sauce if using, and season with salt and pepper to taste.
8. Cook: Set the slow cooker to low for 6-8 hours or high for 3-4 hours. The lamb should be tender and easy to shred.
9. Add Greens: About 30 minutes before serving, stir in chopped spinach or kale, allowing them to wilt in the heat of the curry.
10. Serve and Enjoy: Taste and adjust the seasoning if needed. Serve hot over rice or with naan bread.