This is a very simple recipe from my husband:
1 pound Chicken or lamb cut in cubes, including bones. Heat up karahi and add the meat, do NOT add any fat or salt to it.
Lid on, cook on medium heat, stirring occasionally, until all liquid has dried. The meat should be cooked by now.
Add some salt and oil or ghee, fry for a bit.
Add 1 teaspoon garlic/gingerpaste. When paste dry, add some red chilli powder, ground black pepper, and garam masala if u want to. (Approx 1 teaspoon each).
Then add cut green chillies, squeeze of lemon juice and some 3 or 4 tomatoes cut in wedges. Allow some tomatoes to go a bit soft, the others should keep their shape.
Karahi ready when the oil separates from the rest, it really is very delicious.