King's Cake
The "Kings' Cake" tradition in some French households is that the youngest person hides under the table and says who each piece of the cake will go to as it is cut (so the person cutting the cake, even if the "king" token becomes visible, does not choose the king). You could use the same technique to illustrate that the "unseen force" (God), not people, chose who would become king, although people (Magi) were still instrumental in identifying that king (just like the cake cutter is necessary to distribute the pieces). The tradition continues with each king/queen choosing another person at the table to be their consort, which you could connect with Jesus choosing his disciples.
