Jalfrezi is likely a Raj era invention from Bengal side that has morphed into a dish that appears in many interpretations.
For some, it is Indo-Chinese and requires stock powder, corn starch, and soy sauce. For others, it is a protein like paneer or chicken plus a medley of vegetables. Some like it fairly dry, and others like it in a wet tomatoey gravy. Some people use ketchup in their recipe, and in some restaurant style recipes it is creamy.
However it is made, the common factor in chicken jalfrezi seems to be that it must have bell peppers (aka capsicum) in it. Some people also like onions cut into petals in it. I am not a huge fan of lightly cooked onions, so I don't add those. Here is my very simple and easy version. For this you will need a curry powder type mix like Shan Curry Powder or a Kitchen King Masala. I use MDH Kitchen King Masala.
This recipe is as simple as a daily dish in method, but yields a bell pepper-chicken curry that is unique enough to serve at a party. The soy sauce adds an extra layer of flavor.
1 small organic chicken skinless and cut into karhai pieces (bone in)
1/4 cup oil
4 fresh green chiles, slit but intact
1 small onion diced
1 tsp garlic paste
1 tsp ginger paste
1/4 tsp turmeric
1/2 tsp red chile powder
1 tsp ground cumin powder
1 heaped tsp ground coriander powder
2 medium tomatoes roughly pureed
1 tsp MDH Kitchen King Masala
1 tsp salt or to taste
1/2 tsp soy sauce
one and a half cups bell pepper cut into petals (1/2 inch square pieces)...the number of peppers depends on how large they are. About 3 small or 1.5 of those giant ones.
1/4 cup chopped cilantro for garnish
Method: Heat oil in pan. Add in slit green chiles and allow them to fry for a few moments until they start to slightly soften. Remove with tongs or a slotted ladle. Keep aside to use as garnish at the end of cooking. Add the chopped onion to the oil. Cook this until it is turning golden, then add in the ginger and garlic. Cook this until the ginger and garlic also turn golden. Now add in the turmeric, red chile, cumin, and coriander powder. Allow this to sizzle for a moment, then stir in the tomato. Stir the tomato-masala a bit until most of the water has evaporated from it and the oil has risen to the top of it. Now add in the salt, soy sauce, and MDH Kitchen King Masala. Mix in the chicken and stir well until the chicken has completely changed color and is no longer raw looking. Now cover the pot, turn the flame to the lowest setting, and cook about 10-20 minutes until the chicken is just completely done. You shouldn't need to add water because they chicken will release water as it cooks. If needed, add very little water. When the chicken has just reached the point of being done, add in your bell pepper petals and turn up the heat. Stir for a moment, then lower the heat, cover, and cook for 5 more minutes. You want the bell peppers to cook through but retain a gentle amount of crunch and good color. Now stir in 3/4 of your fresh cilantro. Pour into a serving dish and garnish with remaining cilantro and with the four fried slit green chiles.
Serve with white basmati rice or even Chinese style stir fried rice.