Go out in your yard, gather up as many as you need. Just be sure they haven't been treated with snail bait. All the huge snails in CA are from escaped snails brought in for eating. I think they're from France.
Then you have three pens to put them in, each pen is for a stage of purging. You feed them lettuce etc, and purge them with cornmeal. I don't know how long it takes. But we have a friend who does this all the timie. I'm sure you can google this and get the details.
The large escargot consumed in France is actually purchased from Poland. For some strange reason These GIANT SLUGS resemble Volkswagons crossing the highways.
Will be happy to package and ship anywhere in the world (3 day delivery) live GIANT wild forrest Escargot.
Olstyne Poland- e mail email@example.com