Rogan josh (or roghan josh) is an aromatic curry dish hailing from Kashmir and is quite popular in India, Pakistan, Singapore and the United Kingdom. Rogan (روغن) means oil in Persian, while josh (جوش) means heat, hot, boiling, or passionate. Rogan josh thus means cooked in oil at intense heat. Another interpretation of the name rogan josh is derived from the word rogan meaning color and josh meaning passion, hot or red. So this is a meat dish which is red in color. The red color is essential to this dish and to achieve this end kashmiri mirch, which means "pepper from Kashmir" is used. This ground pepper is red in color but not as hot as other Indian peppers. So a lot of it could be used to impart the red color and yet still keep the food mildly hot.
Rogan josh was brought to India by the Mughals. The unrelenting heat of the Indian plains took the Mughals frequently to Kashmir, which is where the first Indian adoption of Rogan josh occurred.