Semi-Butter Chick'n

Background: Another recipe from my quest for good, home-made Indian food! This is definitely not the butter chicken that is in restaurants, but it's good. I'm still searching for the correct butter chicken recipe...
Originally from: ???
Serves ~4
Approximate time, from prep to table: ~30 minutes

Ingredients:6 Tbsp margarine (or vegan margarine)
2 onions, diced1/2 tsp cinnamon
4 cloves garlic, minced4 tsp ginger powder
1 tsp turmeric2 tsp paprika or Aleppo
2 tsp chili powder2 Tbsp ground coriander
One of the following:-4 cups of chicken, cooked and diced
-4 cups chicken-flavored seitan, diced
-4 cups of chick'n strips, diced -4 cups of cubed tofu (frozen, thawed, and drained well)Optional: 1/4 cup creamy peanut butter
30 oz can petite diced tomatoes
2 Tbsp tomato paste
1 Cup sour cream or plain yogurt (or vegan versions)
Directions:
Melt margarine in a medium saucepan over medium heat. Add the onions and cinnamon and saute until soft:Blend turmeric, paprika, chili powder, and ground coriander in a small bowl. Add garlic and ginger and cook for 1 minute. Add spice mixture to saucepan. Cook, stirring, for 1-2 minutes until fragrant:Add the chicken or chicken substitute, (optional peanut butter), diced tomatoes, and tomato paste. Cover and simmer for 15 minutes:Add the sour cream or yogurt and heat through:I like to let it simmer on the lowest setting for a few more minutes to really blend the flavors while I finish the rice or sidedish, or set the table. Serve over basmati or other rice with naan, chapati, or pita bread.

Note/Tips: This is even better the next day because the spices blend so well over night.