For Butter Chicken from the slow cooker, first chop the onion very finely and place in the bottom of the slow cooker. Cut the meat into bite-sized pieces and layer on top of the onion. Crush or very finely chop the garlic, grate or very finely chop the ginger and mix with the remaining ingredients. Stir well, season to taste and add more seasoning as needed.
Pour this mixture over the onion and meat and cook on HIGH for 3 1/2 hours in the slow cooker. When the time is up, mix everything well, season again and enjoy the Butter Chicken from the slow cooker.