[2-part post]
Maybe you’re being a little pedantic, sp, about what constitutes a “race”. Your strict interpretation is probably scientifically accurate. However, the Race Relations legislation prohibits discrimination of the grounds of race, colour, nationality, ethnic and national origin. In any case, as birdie says, racist incidents do not need to include members of different races to be classified as such. Indeed, since the publication of the ludicrous MacPherson report into the death of Stephen Lawrence, it has been decreed that a racist incident is classified as such if anybody (whether victim or not, whether involved or not) perceives it to be so. So I think my examples are valid as far as that aspect goes.
Indian and Chinese restaurants are not, in my experience, predominantly family run. The reason no non-Indian or non-Chinese workers are found in them is because, as has been said, the jobs are never openly advertised. Accordingly, no white people are likely to have suffered direct identifiable discrimination individually because none is likely to have applied for a job. However, this, and the other reason cited (that the chefs in them rarely speak English) would cut no ice at an employment tribunal or similar enquiries. If it was noted that the majority of “English” restaurants employed only English staff, an investigation would almost certainly be launched by the CRE to establish why this is. As far as I know, no such enquiry has ever been undertaken to discover why the situation in Indian or Chinese restaurants is as it is.