That works for other commands too.
COME
Start preparing food, when ready pup is waiting beside you, move very quickly away from him, say 'pup come' put food down, pup leanrs to come for food.
SIT
Food in bowl, hold over pups head, pup sits, you say 'sit' , pup learns sit means food.
eventually
STAY
Pup is sitting (from previous learning), Say Stay, put bowl down say come (from previosu learning), pup learns stay.