You don't need to dive into full blown Indian restaurant style cooking to make an absolutely delicious chicken madras.
Remove the onions from the microwave. Be careful. They will be hot. Let them cool slightly. Place the onions, 2 tbsp vegetable oil and 1 cup of warm water in a blender and puree until smooth. Set aside.
In a small bowl, combine the mix powder, paprika, Kashmiri chili powder, madras curry powder, kasoor methi and salt. This is your spice mix.
Heat 4 tbsp vegetable oil in a pot over medium heat until it shimmers.
Toss in the cinnamon bark and let cook a few seconds. You will see little bubbles forming around the bark.
Add the onion paste and turn the heat up to medium high. Cook, stirring occasionally for about 4 minutes. The curry will darken a bit as it cooks. Don't worry if it seems a bit dry. The chicken will release juices as it cooks and you should be left with a nice amount of sauce.
Turn the heat down to medium low. Add the chicken and stir. Cover and simmer until the chicken is done. It's done when you measure the internal temperature and it says 170F, about 12-15 minutes. An instant read thermometer is a handy thing to have here...
If the curry is a bit thick add a bit of water or chicken stock and stir. Add a squeeze of lemon juice. Let the chicken madras simmer another minute or so. Taste for salt and adjust as needed.
Garnish with a bit of cilantro and diced red finger hot chili pepper if desired.
The recipe for Indian restaurant spice mix can be found here.
You can buy garlic ginger paste but it's easy to make and homemade is way better. Here's an easy recipe for garlic ginger paste. If you cook Indian fairly often it's so worth it to whip up a batch. It will keep for a few weeks in the fridge.