OK, the title is misleading as I have no way of really justifying this title, but A Casa di Tomilaia is definitely one of the best Italian restaurants in the city. I have been there a few times and the experience is always really good. It probably isn’t a regular place as the food is a little expensive, but the quality and authenticity is really superb and deserving of its Michelin star. The staff are really helpful, so make sure you ask for recommendations as to the daily specials.
A Casa di Tomilaia is just over the river from the ECB tower in Walther-von-Cronberg-Platz, behind the distinctive red Lindner tower. The restaurant serves Toscana specialities and the oils and wines are specially sourced from the region. All of the main courses are between about €12-28 and dinner for two cost me around €70 including drinks and starters, so expensive but not outrageous.
In the Summer, the restaurant spills out on to the terasse and square in front and since there is little or no traffic, the atmosphere is really peaceful. The place is popular most of the time, so book ahead.
I actually benefited from a nice little discount thanks to a book called ‘TasteTwelve‘. This book costs €36, but gives you a free main course at 12 well regarded restaurants in Frankfurt. After 2 meals out the book has more than paid for itself.