An answer I gave to someone regarding whether Jesus ate Kosher food or not:
I believe Christ did make it clear in Matthew 15:11 – not just speaking against the tradition of the Pharisees, but speaking against Israel’s failings in general, who paid so much attention to rules around food, yet there hearts were not right.
1 Tim 4:4-5 has Paul instructing the young minister Timothy that nothing under grace need be refused, which would include meats forbidden under Mosaic law such as pork and seafood.
This would be according to the prophesy of Jeremiah 31:33, where God speaks of a change in heart that no longer requires the letter of the law to bring His people into line. Jesus fulfilled the law (Matthew 5:17), and no Christian is required to adhere to the Mosaic law, Jew or Gentile (Galatians 3:11-13, Colossians 3:11).
I think Peter’s vision was more to do with his own personal bias then what he saw from Jesus. In the crowds of sinners that He fellowshipped with, no doubt were many a Gentile.
That being said, Christ did display a certain obedience to Mosaic law in some contexts, but more to display Himself being the bridge between the death of the law and the life He was bringing through grace (such as eating the Passover to explain that His body would be broken and His blood shed).
I hope that helps.