Coconut as a half and half substitute?

Thank you to you all! The quiche turned out to be delectable (to me)

I ended up using unsweetened cashew milk and tried to add in a bit of fat with some vegan butter. Will try more fat options in the future too

I think coconut milk (full fat) or cream would work in a quiche. I like to use powdered cream of coconut (mixed with a little warm water). It tends to have less coconut aroma and any off odors.

I'm not a big fan of using coconut milk as the substitute for most dairy milk applications, because it always seems to leave behind a slight coconut taste. That's okay for sweet preps, especially when I want a coconut flavor- but not with something like a quiche. In that case, I would suggest you look at using just about any of the other non-dairy "milks" on the market. I would probably lean toward soymilk, but that's me. The thing that will set matters up are the eggs, and the dairy element helps tenderize them, brings some fat, and is the basis for the custard. So if you use a less fat option, add in a bit of fat too- so you don't have a dry quiche. My only other recommendation would be to use a full fat cheese, rather than a low fat one, or your quiche could end up dry and slightly tasteless due to the lack of fat.