I make my own Jalfrezi (the name means fried left overs, like our bubble and squeak by the way). So you can add anything you like. However it used to be the way to use up stock items that were coming to the end of their storage life in in a lot of BIRs!!!!
I use my prepared Chicken Tikka sometimes or just plain prepared chicken
I fry my fresh sliced (1/4 inch) onions, fresh chillis cut in thin strips, and coarser strips of Capsicum peppers (same as onions) in very hot oil for 1 - 2 minutes (depends on amount used). But you want the peppers to be cooked to just before they become al-dente, so that there is some crispness in the finished dish.
Add some chopped fresh (preferred) dry Methi leaves or Methi powder (leaves = smell, powder = taste).
Add some standard base, and some CTM base.
Add some coconut cream block, and dessicated coconut (the latter can be fried at the start just before the onions if you want a deep nutty taste).
Add salt and black pepper to taste.
Add some milk (preferred) or water, not yoghurt or stock.
Add some quarters of ripe tomatoes, briefly fry, and serve.
It is the quickest and simplest dish we do, because it is the last of the batches we cook and we use up the remaining bits and pieces and sauces. It freezes well. Don't try and be precise, this is not the idea for this dish. This is a regular favorite with our customers, and I only did the first one as a bit of a wind up on a friend!
Happy Cooking
C P