Question: When Woody Harrelson is eating the key lime pie in the opening scene, how exactly was that pie made? It looked more translucent like Jello, as opposed to regular key lime pies, which resemble cheese cake.
Answer: My take: The Key Lime pie Mickey eats in the diner looks cheap and trashy on purpose... a garish trailer park version of that pie. The crust isn't even cooked. I think it has more to do with the demographic theme of the diner patrons rather than Harrelson being a vegan.
Answer: Yes, it definitely does not look like a key lime pie. I suspect that because Woody Harrelson is a strict vegan, that it is a substitute made with vegan ingredients.