Bombay Butter Chicken in Crockpot

When I was a kid, my dad was a flight attendant whose regular route was from Hong Kong to Bombay, India. I always wanted to go with him to Bombay because I was madly in love with their magical butter chicken, which they called Murgh Makhani. The complex flavors of sweet onion, garlic, ginger, garam masala, puréed tomaotes, butter and nutmeg or cinnamon exploded in my mouth. Eating Bombay Butter Chicken was heaven on earth so I had to figure out a simple recipe that could be made in my Crockpot.