A lot of people don’t realize that the Five Books of Moses aren’t actually the source of Jewish law. The primary source is the Oral Law that was given along with those books at Sinai. The actual law regarding meat and milk is that you can’t cook meat and dairy together, you can’t eat something that has meat and dairy cooked together, and you can’t derive benefit (sell, feed your pets) from something that has meat and dairy cooked together. Those three are the actual laws that God gave, and the “do not boil a kid in its mother’s milk” verse that’s repeated three times in the Torah is more or less a mnemonic trick to help remember the law. Separate dishes, poultry counting as meat, waiting hours between meat and dairy, these are all additional laws added by the rabbis to provide a margin of error.