Prepare your chicken by lightly seasoning both sides with salt and pepper and set aside.
Preheat your oven to 325º so it is ready to heat up your naan/pita bread. (Skip this step if you have a toaster oven).
Add grapeseed oil (or canola oil) to frying pan with diced yellow onion, minced garlic, butter and chicken thighs. As chicken thighs are cooking begin to baste the chicken by spooning the butter, oil, garlic and onion on top as it cooks. *This will add depth of flavor to the chicken, and will help caramelize the onion and garlic for our delicious sauce!
Let the chicken sear on the first side for 4 minutes while basting it before turning it over. Then once 4 minutes has passed, flip chicken over. Begin to baste the other side for another 3-4 minutes. Remove chicken from heat and let it rest. DO NOT wash your pan yet*
Remove cooked garlic onion and excess fat from pan (put them in a bowl and set aside) Take the same pan and put it back on the heat adding another tablespoon of fresh butter and a chopped shallot. Add your cooked garlic and onion back into the pan let the ingredients begin to caramelize.
Turn your heat down to medium and add chicken stock, tomato paste, crushed tomato, and garam masala into the same pan. Season with ground ginger, chili powder, ground turmeric and cumin.
Occasionally stir and let sauce simmer for about 10 minutes before slicing chicken and adding chicken back in.
Turn heat down to a simmer add in heavy cream and let chicken and tikka sauce simmer for another 20-30 minutes.
In another pot combine basmati rice and chicken broth (or water and chicken base) over medium high heat until it boils. Once rice is brought to a boil turn heat down to low and cover with lid until water is cooked down (about 15 minutes). Cut the heat and let it rest for another 5 minutes.
Take out a baking sheet for your naan/pita bread. Put your naan on the ungreased sheet and place it in the oven to warm for about 2-3 minutes.
It's ready! Plate your chicken tikka masala with basmati rice and use your warm naan for some delicious scooping!