public with sharing class CustomSearchController {
	@AuraEnabled
    public static List<String> searchForIds(String searchText) {
    	List<List<SObject>> results = [FIND :searchText IN ALL FIELDS  RETURNING Account(Id), Contact(Id), Lead(Id)];
    	List<String> ids = new List<String>();
    	for (List<SObject> sobjs : results) {
      		for (SObject sobj : sobjs) {
       			ids.add(sobj.Id);
      		}
    	}
    	return ids;
    }
}