As suggested in the general supermarkets section, many of the popular grocery stores (Thom’s, Namdhari’s, Spencer’s, Reliance, Nilgiris, etc) stock an imported foods section, and most of these chains have also begun producing popular imported foods under their own label, such as pastas, cheeses, sauces, breads, condiments, etc. You will find most items in these stores.
There are also a handful of gourmet imported food stores for when the main grocery chains fail to meet your cravings. Be prepared to spend double what the item costs in your home country though.
Herbs and Spice is a popular delicatessen, patisserie and restaurant in Indira Nagar that sells and serves a variety of fresh fare, including salads, cheeses, quiches, desserts, etc. http://herbsandspice.in.
Sunny’s, on Vittal Mallya Road, is a popular delicatessen and restaurant featuring Italian food and imported ingredients for sale. http://www.sunnysbangalore.in.