What kind of rice to serve with Indian Butter Chicken (Murgh Makhani)?

Basmati is classic. I am particularly fond of brown basmati rice, which has more flavor than white basmati, but it takes longer to cook and will go rancid after 6 months. If basmati is not available, any long-grain rice will suffice; short-grain rice tends to be too sticky.

As for technique, rinse the rice until the rinse-water runs clear. For every cup of rice, use 2 cups of water and 1/2 tsp salt. Bring the water to a boil; add the rice and salt and reduce the heat to a simmer. Cook covered until the liquid has been absorbed and the texture of the rice is tender.

For additions to the rice, you have LOADS of options. You can add a pinch of saffron to the water for a vibrant yellow color and distinctive floral aroma (if you just want color, add 1/2 tsp ground turmeric). You can add chunks of peeled ginger, cracked peppercorns, whole peeled garlic cloves, whole cardamom pods, whole cloves, whole bay leaves, whole kaffir lime leaves, and/or whole stick cinnamon -- amounts and combinations are entirely up to your taste (just remember to remove any bay leaves before serving; remove the others or not as you like, but bay is inedible). You can also add cooked vegetables, such as peas, butter beans, pearl onions, and/or carrots.

I believe that it is de rigueur to use basmati rice when serving northern Indian/Pakistani sauced dishes.

Sautee some finely sliced onions and cumin, add a pinch of mild curry powder, or turmeric for colour, add a handful of frozen petits pois, cook till peas are warmed through, mix in with basmati rice, and you have the easiest pilav ever.