The act of converting a highly flavoursome or spicy dish of african/asian/etc origin, to a bland, dull and less spicy-flavoured version. This consequently makes it suitable for consumption by mainstream english-speaking people who have conservative food tastes. This can also be applied to bland/dull dishes created in the western world but attributed to foreign origins.
The famous curry-influenced cuisine of India was blanderized by the introduction of spiceless packet curry mixes to the shelves of a local supermarket.
Chow mein is a recently created meal of the 20th century, comprising of generic meat, vegetables and spices. It is often attributed to china, but has more local american origins.