Your link is broken so I'm not sure what your diet is, but it isn't as simple as you seem to think.
I'll explain what I know about the process.
Since tryptophan is indeed an essential amino acid, it seems logical to assume that a diet rich in proteins would result in more tryptophan and therefore serotonin. The opposite is actually true. When one eats a meal high in proteins it's been observed that brain and serum levels of serotonin actually decrease. This is because tryptophan makes up only a small part of most dietary protein sources. Since many amino acids compete for common carrier molecules for transport into neurons, brain influx of tryptophan shows a relative decline. I also believe(am not 100% certain) tyrosine takes preference over tryptophan uptake, further complicating matters.
A carb-rich, protein-poor meal will actually increase serotonin even if the protein in question contains little or no tryptophan. This is due to insulin release, which causes muscle cells to uptake LNAAs(large neutral amino acids) and thus increase tryptophan ratios in the brain.
Now, I wanna say again that I don't know what your link said with regards to dietary recommendations. For all I know you said exactly this. However, based on some of your previous posts, it seems to me that you don't understand the complicated nature of amino acid uptake and metabolism, which is the only reason I stepped in here. I do apologize if I have the wrong impression about your understanding.
As I said in a previous thread, it is best to simply have a good, healthy diet in general whether or not one uses mdma(or any other drug). There is no reason to overthink something like this, which is honestly what I think you have a tendency to do Sam.