I admire that you want to prepare vegan food for your cat. However, they require certain nutrients such as taurine, an amino acid that does not exist in plants. If this amino acid is missing from their diet, bad things (I think blindness among others) can occur. You can probably get taurine. However, there may be other (unknown) nutrients present only in animal products that cats need.

Just my opinion, I could be wrong (to quote Dennis Miller.)