As soon as cumin starts to sputter add butter, allow to melt and add the rest of the spices stirring constantly.
after 30-45 seconds add the onions and salt. this will stop the frying. allow the onions to soften and begin to pick up some color. make sure the spices are not burning
add garlic. fry for 1 minute.
Add tomato paste and fry for 2 minute.
Scrape the bottom of the pan, add can of cherry tomatoes. I suggest using a potato masher from this point on to mash everything into a puree. Cook mixture until you can leave a space when you drag your masher on the bottom.
Add broth and scrape bottom of pan. I actually suggest knorr homestyle concentrated stock.
Add chicken. make sure its covered by liquid by adding water as needed.
Once cooked, remove the chicken and allow to cool before hand pulling. Meanwhile increase heat to high and reduce the sauce by 1/3. Add chicken and chili powder.