There should not be an apostrophe (or an "s") after "meat" in this description because the meat does not own the sauce. Therefore, the menu should read like this:
"tortellini with meat sauce"
I guess the only person who could rightfully claim ownership of the sauce would be the person who made it, which is why the apostrophe in "Newman's Own Spaghetti Sauce" is correct.
Therefore, the grammar rule is the same as last time . . .
GRAMMAR RULE: Use an apostrophe to denote possession.