This is incredibly complex and the short answer is it is not possible to create a restaurant that would meet the dietary restrictions of all jews and all muslims. You could create something that would work for some jews and some muslims.

Thing is neither religion is homogeneous about what meets the dietary requirements, there are variations among different sects and factions, since neither religion has a single central authority.

There's much more to both Kosher and Halal than the butchering. Muslims are OK with shellfish for example but that would be treif to a jew keeping kosher.

A vegan or ovo-lacto vegetarian restaurant should work for all muslims and most jews, but the most ultra-orthodox jews would find the lack of rabbinical supervision a problem but they are unlikely to eat out at any restaurant regardless.

Halal can be pretty tough to nail down, about the only thing everyone agrees on is no pork, pretty much the rest of it is open for interpretation. Some muslims think that meat must be specifically prayed over by an imam, other's believe it's sufficient to say a prayer themselves, still others think it's all good as long as what your eating wasn't sacrificed to another (i.e. pagan) god. The koran says "the food of the people of the book is halal" but it seems that most muslims have a different read on that than the literal interpretation that Kosher is, well kosher.