Remember, being lean is the body's natural state. It strives for it. The most important aspect of food in relation to gaining lean muscle is in the timing of food intake. That comes in two parts. Firstly, to have enough energy for your workout, you would want to eat at least 1.5 hours before that workout.
Digestion is the most energy consuming thing our bodies do.
If we eat just before getting to the gym or starting our workout at home, our body is busy digesting. In order to get energy from the food we eat, it must first be digested. This takes at least 1.5 hours. Carbs are the primary source of energy. I suggest rice and vegetables, or some other grain.