STUTTGART: looking for a restaurant for a special birthday celebration
 

I know Stuttgart is the wrong place to look for a gourmet restaurant, however that is the one place that I will be meeting my sister on her birthday in October. We won't have a car to drive out to the gourmet hotel restaurants in the Black Forest. We will be staying in downtown. Any suggestion?

Further research presents me with:

Speisemeisterei 2 star Michelin castle restaurant
Delice. 1 star Michelin
Olivio Steigenberger hotel where I have had dinner, good food but so-so ambiance.
Anybody knows Speisemeister or Delice?