Place the tomato sauce or tomatoes with a little water in a blender with the onion and blend until smooth.The puree should not be too watery.Set aside.
Place the chicken breasts in a pot and cover with water and a pinch of salt.Bring to a boil.Meanwhile wash and chop all veggies,giving the chicken plenty of time to do its thing.
Add the carrots and potatoes to the pot with the chicken(if the chicken still has a long way to go,wait until it is almost done).After about 5 minutes,check for doneness.Remove if they seem soft enough to your liking-remember they need to be firm enough to hold their shape after a brief sautee with the chicken later.If they are still too hard cook a couple more minutes before adding the remaining veggies.
Add the remaining veggies and cook until done but still somewhat crisp.
Drain the chicken and veggies(reserving the broth if you wish,it probably won't be very rich if you only used breasts,but you can still use it for cooking veggies,rice etc.).Let the chicken cool until you can handle it comfortably.Shred the chicken,discarding the skin,bones,and any gristle, cartilage and excess fat.
Heat the oil in a large skillet over medium.Add the reserved tomato puree,and cook for about 5 minutes,stirring often ,until it has concentrated a bit and no longer has a raw flavor.
Add the chicken,vegetables,chiles,raisins,and almonds.Add vinegar,sugar,and spices to taste.Simmer a few minutes ,until everything is hot and the flavors well melded.