You can make flan vegan by omitting the eggs and using Agar which is a semi transparent powder derived from red-purple algae. Make sure you buy powdered Agar not flakes. Substitute the evaporated and condensed milk for coconut milk respectively. I have not tried making Vegan flan so I can't say if the ending result is good. There's a lot of Vegan recipes for flan out there just Google them.