For gastronomic fare at average prices, make sure you book a table at La Rizière. The restaurant is a working culinary school and the chefs and waiters are all perfecting their trade. Service is charming (the chefs come and introduce themselves at the end of the meal) and the dining room phenomenal: a glasshouse with panoramic views of Fianarantsoa.
At lunchtime it can be almost deserted so book a table for the evening and enjoy a bit more atmosphere.