So following this principle laid down in the Old Testament of the Passover Lamb being a foreshadowing of Jesus himself (As Jesus is now recognized as the Lamb of God as stated by John the Baptist), Jesus explains it pretty clearly himself in Matthew 26:26-28 " While they were eating, Jesus took a loaf of bread, and after blessing it he broke it, gave it to the disciples, and said, “Take, eat; this is my body.” 27 Then he took a cup, and after giving thanks he gave it to them, saying, “Drink from it, all of you; 28 for this is my blood of the covenant, which is poured out for many for the forgiveness of sins." The Jews and many of Jesus disciples certainly understood the correlation between the Passover Lamb and what Jesus was saying, which is why they had such a problem with it as we see in John 6:51-55 "
51 I am the living bread that came down from heaven. Whoever eats of this bread will live forever; and the bread that I will give for the life of the world is my flesh.”
52 The Jews then disputed among themselves, saying, “How can this man give us his flesh to eat?” 53 So Jesus said to them, “Very truly, I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. 54 Those who eat my flesh and drink my blood have eternal life, and I will raise them up on the last day; 55 for my flesh is true food and my blood is true drink." The disciples were equally incensed John 6:60-61 "When many of his disciples heard it, they said, “This teaching is difficult; who can accept it?” 61 But Jesus, being aware that his disciples were complaining about it, said to them, “Does this offend you?" We see that to many of his disciples it did which is why in John 6:66 many stopped following him. "Because of this many of his disciples turned back and no longer went about with him." I think that we forget that Jesus is God and created the universe by speaking it into existence as Genesis chapter 1 and John 1:3 states. Jesus was able to multiply food as we see earlier in John 6. So it is a simple matter for him to do as he has said.