The health giving values of a plant based diet is not the only value point.
The much-reduced cost of living, by avoiding animal products, makes it very easy to enjoy any vegetable you choose and there will still be funds left at the end of a week. Another satisfying aspect of a vegan lifestyle, avoiding meat, milk and processed foods, is that our ecological savings are the equivalent of giving up driving a car, or never flying again.
The problem for the cook is to provide meals which are attractive to all comers, most of whom are expecting a meal with meat being the centrepiece of view and/or flavour.
I have produced a graphic chart which divides vegetables up into 6 groupings. If any meal incorporates 4 or more of these groups you can be assured of a fully sustainable meal with sufficient variety to be enjoyable.