The 5 Ways to Cook with Grape Leaves blog that follows looks great:
https://blog.markethallfoods.com/inside-market-hall/5-ways-to-cook-with-grape-leaves
Sautéed Greek grape leaves with lemon juice and olive oil are called Horta. A blog recipe for them follows:
https://foragerchef.com/horta/
Department of Agriculture Information on how to prepare fresh grape leaves:
https://ucanr.edu/sites/default/files/2017-08/266942.pdf
Grape leaves’ nutrient profile follows:
https://foodstruct.com/food/grape-leaves
You might want to check this information with some other sources. I used this site, because I liked the visual presentation of information.
Also, once grape leaves are picked, you can prune back the vines more easily for winter. The wood trimmings can be recycled and used in baking paper.
Reposted by Ruth Paget, author Eating Soup with Chopsticks and Marrying France