For this Butter Chicken or Murgh Makhani, you have to make Tandoori chicken and then the Butter Chicken Gravy. I have found an easier way to do this. I first marinate the chicken and roast it in a pan instead of grilling it and then give it the Dhungar treatment.
Garlic mushrooms Recipe has mushrooms tossed in a pan and then added to the garlic sauce. Crushed garlic and Onion sautéed till pink with coloured peppers makes the base for this sauce. Once the mushrooms are added, add a cornflour slurry to thicken the sauce.