Walnuts the toasted walnuts in a food processor or Mini-Prep and blitz until they look like coarse meal. Set aside.Saute the onions in 2 T of butter or olive oil for about 5 minutes. Add toasted walnuts and cook for another 2 or three minutes, stirring. Add pomegranate molasses, chicken stock and lemon juice and stir to combine. Remove from heat, put into a bowl and set aside.In a medium-sized bowl, mix cinnamon, turmeric, brown sugar, salt and pepper. Using your hands, coat each piece of chicken with the spice mixture. Add 1 tablespoon of butter or olive oil to the pan you sauteed the onions in. Working in batches, brown the chicken on both sides.Put the chicken in the slow cooker and top with the onion and walnut sauce. Scatter garlic cloves and rosemary stems over the sauce. Start slow cooker on high, until sauce begins to bubble then turn down to low and cook for 3 1/2 hours. Add carrots to slow cooker and stir to combine with sauce. Continue cooking on low for another hour.Garnish with pomegranate seeds and chopped parsley. Serve over herbed basmati rice.