Beat egg whites in another large bowl with cleaned beaters at medium speed until they just hold soft peaks. (epicurious.com)
Beat cream with sour cream and sugar using cleaned beaters at high speed until it just holds soft peaks. (epicurious.com)
Get out your mixer again (don't even worry about cleaning the beaters... it's all going to be combined in the end) and whip the coconut milk on high for several minutes until you've got a nice whipped consistency. (namelymarly.com)