You can make it yourself by all means but I’ve found the frozen ones here in Japan to be pretty good.
Gyoza maxi 😤
Discussion
I know how yummy those frozen ones are since I live in Korea. :-) When discussing how to make ravioli, people don't expect it to be made from a can. (don't be serious. I was jocking) Anyway, have good one! 
BTW, I also like ravioli from a can.