In a small bowl combine 1Tbsp. of the garam masala, ginger, salt, chili powder and allspice.
In a glass measuring cup combine the vegetable stock, red curry paste, and tomato paste whisking to combine well.
Place the chicken in the crock pot and add the vegetable stock mixture. Stir a couple of times.
Add in the spice mixture, onions and tomatoes and mix well. Cover.
Cook on low for about 3 hours.
Mix the yogurt with the remaining tablespoon of garam masala. Add to the chicken. Let it sit for about 10 minutes. Add in the cilantro.
Serve with basmati rice or naan.