Perhaps Bridget Foys? I think they do the brunch thing now on Saturdays (most places do) but it's a pretty varied menu. I wouldn't call it a leisurely meal, but I've never felt rushed either. The blood orange mimosa is delicious, and they have a decent selection of good beers and wines. You might be looking for something a bit fancier, but I've always enjoyed myself here. And I think the I-95 exit on Columbus Blvd is very close to this. I was also thinking of Fork or Farmacia in Old City, but I don't think they are even open till dinner on Saturdays.