1. Garam Masala - A combination of spices (white and black peppercorns, cloves, cinnamon, black and white cumin seeds, cardamom pods) that you can usually just pick up an an Indo-Pak grocery store already combined.
2. Tumeric (Haldi) - This stuff will stain your clothes, your hands, and your counter-top, so be careful!
6. Cilantro - You can grow your own or buy them fresh. I get it at the local grocer for .25 cents a bunch, so I always have it in the fridge, even if I don't end up using it.
7. Salt - Most homes already have salt, but this is really important and you use a good amount of it!
10. Cardamoms and Cardamom Powder - This gives the food a nice fragrance.
12. Mustard Seeds - Also something that is roasted to add flavor.
13. Curry Leaves - You don't always need to have these fresh, you can use dried curry leaves or freeze them.
15. Basmati Rice & Bread - All dishes are either served with rice or a bread (naan, paratha, chapati, etc.). Both are necessary. The brand of rice does make a difference and I recommend either Reserve or Royal.
And lastly, there are some fresh produce that you should always have in your fridge or freezer that will help to cook up some quick dishes, such as: tomatoes, potatoes, peas, carrots, spinach, onions.
If you have these ingredients, you are well on your way to cooking Pakistani!