Many of my dishes call for peeled tomatoes, which are easy to prep. The traditional method is to cut an X into the nonstem end of each tomato with a sharp knife and blanch them. To do so, drop them in boiling water for a little less than a minute, until the peel starts to pull away. Pull the tomatoes out of the water using tongs, drop them in an ice bath, and once they’ve cooled, they will peel easily. The fastest way to peel tomatoes without blanching is to use a serrated peeler, one of my favorite gadgets.
Yogurt (dahi): Indians have a cultural affinity for yogurt. It’s present at every meal. The kind we typically eat is homemade and is thinner and more tart than the kind sold in supermarkets. If you are going store-bought, look for unsweetened, plain yogurt. If you have the patience to make it at home (it’s not hard—check out my recipe in The Indian Slow Cooker), and have an Indian friend who can give you some culture, you’ll never, ever go back, and you’ll save a ton of money.