Two factors I would recommend are:

1. An open policy that all cultures are to be respected and valued. School activities can held to allow all (staff and learners) to participate. This allows exposure to different beliefs system. Many times traditions are continued when understanding is limited. 

2. A clear indication that diversity is valued at the school. Anyone being recruited will need to be open minded and understand that personal biases will not be accepted. It is part of being professional and is engrained in the ethos and culture of the school. 

I have personally experienced both factors recommended above. These have contributed to me being more open minded and respectful for all I interact with.