Dr. La Puma still cooks and gives lectures and demonstrations to conferences and groups. He is now also an organic farmer and owns a Santa Barbara regenerative farm where he makes dishes for guests.
The other doctors mentioned are vegan, nutritionists and physicians, but not trained chefs.
Dr. Elizabeth Ko at UCLA is one.
https://www.uclahealth.org/providers/elizabeth-ko
Dr. Linda Shiue is another.
https://www.plantforwardkitchen.org/linda-shiue
Dr. Bob Graham is a third.
https://www.freshmednyc.com/dr-robert-graham-integrative-medicine-nyc
Like Dr. La Puma, they're omnivores, and write pretty simple, tasty recipes.